Cyclin-dependent kinases 4 and 6 (CDK4/6)

Cyclin-dependent kinases 4 and 6 (CDK4/6) are serine/threonine kinases that play a central role in regulating the cell cycle, specifically the transition from G1 phase to S phase. They function as part of complexes with D-type cyclins, and their activity is essential for cell proliferation. Dysregulation of the cyclin D–CDK4/6–Rb axis is common in many cancers. Selective inhibitors targeting CDK4/6 have become important therapies for certain cancers, primarily hormone receptor-positive/HER2-negative breast cancer.

Selective inhibition of CDK4/6, leading to RB-dependent proliferative arrest and potential impacts on DNA repair mechanisms and immune modulation within tumors.