Epigenetics, the storage of genetic information outside of the DNA relies on methylation. E.g. a smoking grandfather can cause problems for his grandchildren, even though this information is not stored inside the DNA but in the methylation patterns which are also inherited. It will be interesting how much epigenetics will have an influence on the prevention and cure of cancer.

https://en.wikipedia.org/wiki/Cancer_epigenetics

"As Vogelstein et al. point out, in a colorectal cancer there are usually about 3 to 6 driver mutations and 33 to 66 hitchhiker or passenger mutations.[2] However, in colon tumors compared to adjacent normal-appearing colonic mucosa, there are about 600 to 800 heavily methylated CpG islands in promoters of genes in the tumors while these CpG islands are not methylated in the adjacent mucosa."