The Two-Hit Hypothesis

The Two-Hit Hypothesis is a theory in cancer research suggesting that two specific genetic mutations (or "hits") are typically required for a normal cell to become cancerous. The first hit often occurs in a gene that controls cell growth, and the second hit leads to further dysfunction. This concept explains why certain cancers, like retinoblastoma, are more likely in individuals with a hereditary predisposition—having one mutation increases the risk of acquiring the second, leading to cancer development. Essentially, it's a model to understand how genetic events can accumulate over time to result in cancer.