Flow cytometry analysis demonstrated an obvious G1-arrest, as evidenced by the decrease of cell events in S phase in CS-1 (Fig. 4A and C) and SW1353 cells after palbociclib treatment for 24 h (both P < 0.01) (Fig. 4B and D), indicating the attenuation of CDK4 was capable of facilitating the cell cycle arrest of chondrosarcoma cell in G1 stage, thereby abrogating DNA synthesis. Here, CDK4 is linked to chondrosarcoma.