[{"from": "human", "value": "Provide a brief overview of this molecule. [C][N][Branch1][C][C][C][=Branch1][C][=O][C][=C][C][=C][N][=C][Branch1][#C][N][=C][Ring1][=Branch1][N][Ring1][=Branch2][C][C][C][C][C][Ring1][Branch1][N][C][=N][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][N][C][C][N][C][C][Ring1][=Branch1]"}, {"from": "gpt", "value": "The molecule is an orally available cyclin-dependent kinase (CDK) inhibitor targets at cyclin D1/CDK4 and cyclin D3/CDK6 cell cycle pathway, with potential antineoplastic activity. Ribociclib specifically inhibits CDK4 and 6, thereby inhibiting retinoblastoma (Rb) protein phosphorylation. Inhibition of Rb phosphorylation prevents CDK-mediated G1-S phase transition, thereby arresting the cell cycle in the G1 phase, suppressing DNA synthesis and inhibiting cancer cell growth. Overexpression of CDK4/6, as seen in certain types of cancer, causes cell cycle deregulation."}]