Answer:
Tumor-suppressor gene.
Step-by-step explanation:
The mutation in the normal cells can lead to the cancer in the body. Two main types of genes mutation that may lead to cancer are proto oncogenes and tumor suppressor genes.
Tumor supressor genes regulates the division of cell cycle and acts as a gate keeper for the normal cells. The loss of function mutation in tumor suppressor gene leads to the formation of cancer. The gene that are involved in apoptosis and its mutation leads to leukemia. This gene is acting as tumor suppressor gene.
Thus, the answer is tumor-suppressor gene.