Cordycepin suppressed FGF9-induced expression of CDK4, CDK2 and CDK1 in MA-10 cells. (A) Western blot analysis for the expression of CDK4, CDK2 and CDK1 in MA-10 cells were treated without or with FGF9 (50 ng/mL) and different concentrations of cordycepin (0, 25, 50 and 100 µM) for 0.25, 12 and 24 h. (B–D) The relative expression of (B) CDK4, (C) CDK2, and (D) CDK1 was quantified using ImageJ software by normalization with β-actin. Values are shown as the mean ± SEM, n = 4. p values were calculated using two-way ANOVA with Tukey’s multiple comparisons post-tests. * p < 0.05, *** p < 0.001 compared to the control group (0 ng/mL FGF9) at each dose of cordycepin; # p < 0.05, ## p < 0.01, ### p < 0.001 compared to the group with 0 μM cordycepin and 50 ng/mL FGF9 treatments.