Rafael Sirera

Professor of Cell Biology at Universitat Politècnica de València, with a particular passion for molecular medicine and a strong interest in natural philosophy.

[Rafael Sirera @ProfSirera]

Stellar Moments in Biology: A Journey Through the Discoveries That Explained Life.
A guide to the great questions of biology and to the remarkable moments when new evidence changed the way we understand life.
Definitively, the book I would have loved to have during my own university studies.
For a limited time, the ebook is available in your local amazon site for only US$1.50. The paperback edition is also available worldwide.
https://t.co/Shs0cffHSD

[Rafael Sirera @ProfSirera]

Urine is far more than waste — it is a remarkable window into our physiology and health.
And with advances in molecular diagnostics and liquid biopsy, its diagnostic potential is expanding well beyond conventional urine tests!

[Rafael Sirera @ProfSirera]

@KhaledAAAlobaid Thanks for the valuable insight

[Rafael Sirera @ProfSirera]

Urine is far more than waste — it is a remarkable window into our physiology and health.
And with advances in molecular diagnostics and liquid biopsy, its diagnostic potential is expanding well beyond conventional urine tests!

[Rafael Sirera @ProfSirera]

@KhaledAAAlobaid what do you mean with invasive? upper parts of urinary system like renal candidiasis or some complicated pyelonephritis?

[Gill Gross 🎺 @Gill_Gross]

Your lazy guide for Turin head-to-heads.

[Rafael Sirera @ProfSirera]

Mientras las células de Henrietta Lacks inmortalizaron su nombre en los laboratorios del mundo, las de Mary Papanicolaou salvaron millones de vidas en silencio, recordándonos que la ciencia también se construye con heroínas anónimas. https://t.co/3QAT6B0Jte

[Rafael Sirera @ProfSirera]

@OGdukeneurosurg Textbooks: every nerve neatly named and colour-coded.
Reality: ‘Where the hell is the label on this one?

[Rafael Sirera @ProfSirera]

George y Mary Papanicolaou: la mujer que prestó sus células para salvar millones de vidas. Listen to it on @ivoox! https://t.co/3QAT6B1hiM

[Rafael Sirera @ProfSirera]

Mientras las células de Henrietta Lacks inmortalizaron su nombre en los laboratorios del mundo, las de Mary Papanicolaou salvaron millones de vidas en silencio, recordándonos que la ciencia también se construye con heroínas anónimas. https://t.co/3QAT6B0Jte

[Rafael Sirera @ProfSirera]

A new paradigm in breast cancer: treating resistance before the cancer progresses.

What if we could detect that a cancer is developing resistance to treatment before it actually starts growing again?
This is no longer hypothetical. The phase III SERENA-6 trial demonstrates how liquid biopsy can transform treatment decisions in advanced breast cancer.

Patients with hormone receptor-positive (HR+), HER2-negative advanced breast cancer commonly receive an aromatase inhibitor (AI) combined with a CDK4/6 inhibitor as first-line treatment.

However, tumours evolve.

Under the selective pressure of endocrine therapy, mutations in ESR1, the gene encoding oestrogen receptor α, can emerge. These mutations allow the receptor to remain active even when oestrogen levels are suppressed, undermining the effectiveness of aromatase inhibitors.

Here is where the paradigm changes.

Instead of waiting for radiological progression, SERENA-6 used serial circulating tumour DNA (ctDNA) analysis to detect emerging ESR1 mutations.

When a mutation appeared, patients without disease progression were randomised to continue their current treatment or switch their aromatase inhibitor to camizestrant, an oral selective oestrogen receptor degrader (SERD), while maintaining CDK4/6 inhibition.

The updated results are compelling:

- Median progression-free survival: 16.8 versus 9.2 months (HR 0.45).
- Median second progression-free survival (PFS2): 25.7 versus 19.1 months (HR 0.63).

Although an overall survival benefit has not yet been established, these findings demonstrate that molecularly guided treatment adaptation can substantially delay progression.

In September 2026, the FDA granted accelerated approval to this strategy.

This is more than another targeted therapy. It represents a fundamental change in how we manage cancer.

Traditionally, we modify treatment when disease progression becomes clinically or radiologically evident.
Now, liquid biopsy allows us to identify an emerging resistance mechanism and intervene while the disease remains controlled.

We are moving from reacting to tumour progression to anticipating and intercepting molecular resistance.

That may be one of the most important contributions of precision oncology.

Thank you, Prof. @ElJanLe & @isliquidbiopsy, for bringing this exciting advance to my attention!

[Antonio Rivera @meteolp]

1/ 🧵 La borrasca #Charles ha llegado más débil de lo que anunciaban los modelos días antes. Y vuelve la pregunta: «si no aciertan a 48 horas, ¿cómo vais a saber qué pasará en 2100?». Es lógica, pero compara cosas distintas. Vamos por partes 👇

[Rafael Sirera @ProfSirera]

@meteolp O dicho de otra manera: el clima te ayuda a decidir qué ropa comprar; el tiempo decide si te arrepientes de habértela puesto. Un hilo muy útil, @meteolp

[Rafael Sirera @ProfSirera]

A new paradigm in breast cancer: treating resistance before the cancer progresses.

What if we could detect that a cancer is developing resistance to treatment before it actually starts growing again?
This is no longer hypothetical. The phase III SERENA-6 trial demonstrates how liquid biopsy can transform treatment decisions in advanced breast cancer.

Patients with hormone receptor-positive (HR+), HER2-negative advanced breast cancer commonly receive an aromatase inhibitor (AI) combined with a CDK4/6 inhibitor as first-line treatment.

However, tumours evolve.

Under the selective pressure of endocrine therapy, mutations in ESR1, the gene encoding oestrogen receptor α, can emerge. These mutations allow the receptor to remain active even when oestrogen levels are suppressed, undermining the effectiveness of aromatase inhibitors.

Here is where the paradigm changes.

Instead of waiting for radiological progression, SERENA-6 used serial circulating tumour DNA (ctDNA) analysis to detect emerging ESR1 mutations.

When a mutation appeared, patients without disease progression were randomised to continue their current treatment or switch their aromatase inhibitor to camizestrant, an oral selective oestrogen receptor degrader (SERD), while maintaining CDK4/6 inhibition.

The updated results are compelling:

- Median progression-free survival: 16.8 versus 9.2 months (HR 0.45).
- Median second progression-free survival (PFS2): 25.7 versus 19.1 months (HR 0.63).

Although an overall survival benefit has not yet been established, these findings demonstrate that molecularly guided treatment adaptation can substantially delay progression.

In September 2026, the FDA granted accelerated approval to this strategy.

This is more than another targeted therapy. It represents a fundamental change in how we manage cancer.

Traditionally, we modify treatment when disease progression becomes clinically or radiologically evident.
Now, liquid biopsy allows us to identify an emerging resistance mechanism and intervene while the disease remains controlled.

We are moving from reacting to tumour progression to anticipating and intercepting molecular resistance.

That may be one of the most important contributions of precision oncology.

Thank you, Prof. @ElJanLe & @isliquidbiopsy, for bringing this exciting advance to my attention!

[William Aird @WilliamAird4]

1/2

TWO WAYS TO DRAW COAGULATION

Why do we still teach the coagulation cascade?

Because it helps explain the PT and aPTT.

[Rafael Sirera @ProfSirera]

Personalised medicine and molecularly targeted therapies are at the heart of modern oncology and haematology.

Leukaemias are a remarkable example of how understanding the molecular mechanisms driving cancer has transformed treatment: from inhibiting oncogenic kinases and restoring cellular differentiation to targeting epigenetic regulators and exploiting specific cell surface antigens.

The future of cancer treatment lies not simply in knowing where a tumour originates, but in understanding what makes it biologically vulnerable.

[Rafael Sirera @ProfSirera]

@crubiom1 Gracias. Se publicará en abril. Estaré encantado !!

[Rafael Sirera @ProfSirera]

@crubiom1⬇️⬇️

[Rafael Sirera @ProfSirera]

Me siento profundamente honrado de compartir que mi libro "Por la humanidad. La conquista de la inmunidad: una historia de ciencia y perseverancia" ha resultado finalista del prestigioso Premio Europeo de Divulgación Científica Estudio General - Ciudad de Alzira, convocado por la Universitat de València (@AjuntAlzira, @UV_EG).
Para mí, es un magnífico reconocimiento al esfuerzo invertido en esta obra, con la que he podido acercar la historia de la inmunología a la sociedad. Mi más sincero agradecimiento al jurado, a las instituciones organizadoras y a @bromera, la editorial que publicará el libro.
¡Seguimos sumando en la labor de divulgar!

[Rafael Sirera @ProfSirera]

@mcarmen_collado ⬇️⬇️

[Rafael Sirera @ProfSirera]

En el nuevo episodio de "Ciencia a dos" descubrimos la historia de George y Mary Papanicolaou, una pareja cuya perseverancia revolucionó la detección precoz del cáncer de cuello uterino y contribuyó a salvar millones de vidas.

Porque él dio nombre a la prueba, pero ella puso, literalmente, una parte de sí misma en el descubrimiento.

¡Descubre su historia! https://t.co/2GNhvRCM1f

[Rafael Sirera @ProfSirera]

En el nuevo episodio de "Ciencia a dos" descubrimos la historia de George y Mary Papanicolaou, una pareja cuya perseverancia revolucionó la detección precoz del cáncer de cuello uterino y contribuyó a salvar millones de vidas.

Porque él dio nombre a la prueba, pero ella puso, literalmente, una parte de sí misma en el descubrimiento.

¡Descubre su historia! https://t.co/2GNhvRCM1f

[Rafael Sirera @ProfSirera]

@meteolp Gracias @meteolp. Su lanzamiento es para la feria del libro en Abril

[Antonio Rivera @meteolp]

Con muchas ganas de leer este libro de @ProfSirera que ha quedado finalista en el prestigioso premio Premio Europeo de Divulgación Científica Estudio General - Ciudad de Alzira.