CDKN1A and osteosarcoma: Fig. 2B shows the statistical representation of Fig. 2A. Moreover, Western blotting showed dramatic increases in the protein levels of p21 and p27 [22]—two critical cell cycle inhibitors—in hyperoside-treated cells in a time-dependent manner (Fig. 2C), indicating that p21 and p27 are involved in hyperoside-induced G0/G1arrest. These results suggested that the inhibition of proliferation in osteosarcoma cells results from hyperoside-induced cell cycle G0/G1 arrest.