Question

cyclin - dependent kinase inhibitors are being investigated as cancer treatments because
many cancers are caused by mutations in cdk pathways.
cdk inhibitors are safe to use in normally dividing cells.
inhibiting one cdk completely shuts down the entire cell cycle.

Explanation:

Cyclin - dependent kinases (CDKs) play crucial roles in regulating the cell cycle. Mutations in CDK pathways are associated with cancer development. By inhibiting CDKs, it can potentially disrupt the abnormal cell cycle progression in cancer cells. CDK inhibitors are not necessarily safe for all normally dividing cells (e.g., some normal cells may also be affected depending on the specificity of the inhibitor). Also, inhibiting one CDK does not completely shut down the entire cell cycle as there are multiple CDKs and compensatory mechanisms in the cell cycle regulation.

Answer:

many cancers are caused by mutations in CDK pathways.