Category: Everyday Science | Last updated: 2026-09-18
The p53 tumor suppressor gene is known as the guardian of the genome because it:
A) Promotes cell division
B) Arrests the cell cycle or induces apoptosis in cells with DNA damage
C) Replicates DNA
D) Only affects liver cells
Explanation
p53: activated by DNA damage → upregulates p21 (CDK inhibitor) → G1 arrest. If damage irreparable, triggers apoptosis. Mutated in >50% of human cancers.