CDK4/6 Inhibitor (related to MHS research)

**What it means:** CDK4 and CDK6 are proteins closely related to CDK2. They all work together to drive cell division. CDK4/6 inhibitors (like palbociclib, ribociclib, abemaciclib) are already FDA-approved for breast cancer and work by blocking the cell cycle at the G1 phase — essentially putting cells in "wait mode" so they can't multiply. **Why this connects to MHS:** Culmerciclib (also called Saitanxin) is a **triple inhibitor** — it blocks CDK2, CDK4, AND CDK6 all at once. This is interesting because it suggests that targeting the entire CDK family (not just CDK2) might be the right approach for MHS, since all three proteins are involved in the same cell cycle pathway.