Question 1
In sporadic cases of retinoblastoma, how many gene mutations are thought to be necessary in the same cell for a tumor to develop?
◦ one
◦ two
◦ four
◦ six
◦ insufficient information to answer this question
Question 2
Which protein appears to regulate the entry of cells into an S phase? This protein is also known as the "guardian of the genome."
◦ cyclin
◦ p53
◦ phosphokinase
◦ p102
◦ p34