Or they can occur in proto-oncogenes, which normally code for proteins that promote the cell cycle - so they're the cell cycle's accelerator pedal.

基因突变也可以发生在原癌基因；原癌基因的功能是编码促进细胞周期运转的蛋白质，所以它算是细胞周期的“油门”。

Mutations can occur in tumor suppressor genes, which normally code for proteins that stop the cell cycle or promote apoptosis - so they're the cell cycle's very own brake pedal.

基因突变可能会发生在抑癌基因；抑癌基因的功能是编码、阻断细胞周期，或促进凋亡的蛋白质，所以它算是细胞周期的“刹车片”。

If only one p53 gene in the pair is mutated, the other gene will still be able to control the cell cycle.

如果该对中只有一个P53基因发生突变，另一个基因仍能控制细胞周期。