**Core Concept**
Tumor suppressor genes are crucial for maintaining genomic stability and preventing cancer development. They encode proteins that regulate cell growth, DNA repair, and apoptosis, ensuring that damaged cells do not progress to malignancy.

**Why the Correct Answer is Right**
The correct answer is a gene that, when mutated or overexpressed, contributes to oncogenesis rather than preventing it. This gene is involved in cell proliferation and survival pathways, promoting tumor growth and metastasis.

**Why Each Wrong Option is Incorrect**
* **Option A:** This gene is a well-known tumor suppressor that encodes a protein involved in DNA repair and apoptosis. Mutations in this gene are associated with various cancers, including breast and ovarian cancer.
* **Option B:** This gene is a classic tumor suppressor that regulates cell cycle progression and inhibits cell proliferation. Loss-of-function mutations in this gene are a common feature of many cancers.
* **Option C:** This gene is a proto-oncogene that, when mutated or overexpressed, can contribute to tumorigenesis. It encodes a protein involved in cell signaling pathways that promote cell growth and survival.

**Clinical Pearl / High-Yield Fact**
Tumor suppressor genes, such as TP53 and BRCA1, are often inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene is sufficient to increase cancer risk. Understanding the function and clinical significance of tumor suppressor genes is essential for targeted cancer therapies and genetic counseling.

**Correct Answer:** D.