E.g., melanomas still produce pigments. Most cancers are derived from a single cell. Cell grows faster and divides faster, therefore is selected. Cancer is a result of somatic mutations, those that occur in scattered individual cells of the mature body. Cancer is a consequence of mutation and natural selection within a population of cells.
Cancer requires an accumulation of mutations.
Cancers develop slowly and can take 10-20 years to reach full malignancy. 24-11 cervical cancer progression in pap smears 7. Tumor progression involves successful rounds of mutation and natural selection. Both wounding and tumor promoters probably act by inducing the expression of genes that were mutagenized by exposure to the initiator. The development of a cancer generally involves many steps, each governed by multiple factors, some dependent on genetics, others on the environment or way of life.