Neoplasia USMLE Step 1 Practice Question
A 4 year old boy is diagnosed with bilateral retinoblastoma. Genetic testing reveals a germline loss of one copy of the RB gene, and the tumor developed after somatic loss of the second copy in retinal cells. Which of the following best describes the normal function of the RB protein?
Answer choices
- ADNA mismatch repair during replication
- BInhibition of the G1 to S transition by binding E2FCorrect answer
- CActivation of receptor tyrosine kinase signaling
- DRepair of double stranded DNA breaks by homologous recombination
- EPromotion of mitochondrial cytochrome c release
- FRegulation of telomerase activity in dividing cells
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