Everybody gets random #mutations in the #DNA throughout life. The amount of mutations increases with age. Most mutations are not harmful and go unnoticed. Some mutations are harmful and affect cell physiology. These mutations are named "driver mutations" that lead to #cancer.
Once cells become unstable because of driver mutations, it leads to many other mutations known as "passenger mutations". Now the next big question is that if the mutation is very common in all individuals why do only some people get the disease?
The most common irregularity leading to #cancer is #gene#mutation. The cell is the building block of our body and DNA is part of each cell. DNA is made up of four #nucleotide bases and has a fixed sequence of these bases. Any change in the sequence of DNA is called a mutation.
The X chromosome carries the genes responsible for the most common type of colorblindness. As women have 2 X #chromosomes so even if one has issues other one makes up for that.