You are presented with the quiz "One tumor suppressor protein which often results in cancer when it stops functioning is:" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "cancer is a disease that occurs when the cell cycle is no longer regulated" and "another critical protein in regulating the cell cycle is the tumor suppressor protein p53 ". 

So, what's the best answer to the question?


 

  p53         