The nature and development of cancer: Cancer mutations and their implications
Cancer is a genetic disease in which progressive accumulation of mutations in the genome of somatic cells induces abnormal biological capabilities. Cancer-inducing mutations may originate from single base substitutions or large chromosomal rearrangements; but ultimately they disrupt normal cellular processes by altering protein function or disturbing the regulation of gene expression. Loss-of-function mutations in tumour suppressor genes inactivate physiological control of cell processes, whereas gain-of-function mutations directly affect physiological networks and, for example, induce pathological activation of signalling pathways. For many common cancers, we are now close to defining unique sets of somatic alterations which confer a specific signature of the cancer type and are also highly specific to the individual patient.