CDK4 and gastric cancer: The CCK8 assay was used to detect the viability of neferine on gastric cancer cells; the monoclonal assay was used to verify the ability of neferine to inhibit colony formation; flow cytometry was used to detect that neferine induced apoptosis and blocked the cell cycle of gastric cancer cells; and qRT-PCR and Western Blot were used to detect that neferine inhibited gastric cancer proliferation by inhibiting the expression of the cycling complexes CDK4/CDK6/CyclinD1.