Which of the following is a type of mutation associated with cancer?

Cancer is often associated with various types of mutations that affect the way cells regulate their growth and division. Gain of function mutations typically enhance the activity of a gene, often leading to the continuous proliferation of cells, a hallmark of cancer. These mutations can occur in proto-oncogenes, which normally promote cell growth and survival. When mutated, they can become oncogenes, driving increased cell division and contributing to tumor formation.

On the other hand, loss of function mutations can deactivate tumor suppressor genes that normally act to control cell division and promote apoptosis, or programmed cell death. When these genes are rendered inactive due to mutations, it removes crucial regulatory breaks on cell growth, allowing cells to proliferate uncontrollably, which is another pathway by which cancer can develop.

Combining these insights, both gain of function and loss of function mutations play significant roles in the carcinogenic process. This is why the choice indicating both types of mutations is correct, as they contribute distinctly and critically to cancer development.