Figure 1From: Epimutations, Inheritance and Causes of Aberrant DNA Methylation in CancerAlternate mechanisms of Knudson's two-hit hypothesis. Diagram a) illustrates the original hypothesis in which two 'hits" affect both alleles of a particular gene. Diagram b) demonstrates methylation occurring as the second hit in unison with a pre-existing mutation. Diagram c) represents an individual with a soma-wide epimutation. The second allele can then also be lost due to methylationBack to article page