CDK6 (Cyclin-dependent kinase 6) is a protein kinase that belongs to the CDK family, which plays a significant role in the cell cycle. It is involved in driving the cell cycle from the G1 phase into the S phase by forming complexes with D-type cyclins (D1, D2, and D3). CDK6, along with CDK4, phosphorylates the retinoblastoma (Rb) protein family, leading to the release of E2F transcription factors and enabling G1 to S phase progression and DNA synthesis. CDK6 is not only important for cell cycle regulation but also has kinase-independent functions, such as acting as a transcriptional regulator. This dual functionality makes CDK6 an attractive target for therapeutic intervention in various types of cancer, including hematopoietic malignancies, breast cancer, and melanoma.