MAPK3 and neoplasm: We found that PEDF had no effect on phosphorylated AKT but upregulated the levels of Thr202/Tyr204-phosphorylated ERK1/2 (Figure 3b and Supplementary Figure 4a), suggesting that ERK1/2 signaling, as indicated by ERK1/2 phosphorylation, is involved in tumor-promoting effects induced by PEDF.