## Core Concept
Oncogenes are genes that have the potential to cause cancer. They can become activated (or "turned on") as a result of mutations. In their normal, unaltered state, these genes play roles in promoting cell growth and division, but when mutated or overexpressed, they can promote uncontrolled cell growth and tumor formation.

## Why the Correct Answer is Right
Oncogenes, when altered by mutation, can lead to the production of abnormal proteins that contribute to cancer development. These genes can be involved in signaling pathways that control cell growth, apoptosis, and DNA repair. The correct statement regarding oncogenes would highlight their role in cancer causation through gain-of-function mutations.

## Why Each Wrong Option is Incorrect
**Option A:** Typically, statements about oncogenes being involved in cell cycle regulation, promoting cell growth, or being activated by mutations would be true and thus incorrect as an "except" choice.
**Option B:** If a statement about oncogenes notes their discovery in viruses (as viral oncogenes) and their role in causing cancer when transferred to host cells, this would also be a true statement about oncogenes.
**Option C:** Oncogenes can result from mutations in proto-oncogenes, which are normal genes that can become oncogenic due to mutations. A statement acknowledging this process would be accurate.
**Option D:** This option is not provided, but typically, an incorrect statement might claim that oncogenes are inactivated by mutations (which is more characteristic of tumor suppressor genes) or that they are exclusively inherited.

## Clinical Pearl / High-Yield Fact
A key point to remember is that oncogenes act in a dominant manner; a single copy of the mutated gene can lead to cancer. This is in contrast to tumor suppressor genes, which often require both copies to be inactivated to lose their protective effects.

## Correct Answer: D.