Two-Hit Hypothesis

The Two-Hit Hypothesis suggests that some diseases, like certain cancers, develop after two genetic changes (mutations) occur in a cell. The first mutation might make the cell partly abnormal, but not dangerous on its own. The second mutation, happening later, pushes the cell into uncontrolled growth, leading to cancer. This model explains why some people with inherited mutations develop the disease only when they acquire an additional mutation, emphasizing the importance of multiple genetic factors in disease development.