RB1 and neoplasm: In the present study, we have a novel finding that cordycepin inhibited MA-10 cell proliferation in vitro and tumor growth in vivo through suppressing the FGF9 signaling pathway, which upregulated the phosphorylation of ERK1/2 and Rb, the expressions of E2F1 and the cell cycle related proteins, cyclins and CDKs (Figure 10).