SPP1 and melanoma: Interestingly, among the strongly repressed genes (67 genes, downregulated >8-fold, P<0.005; Figure 3A and Table S1) are insulin-like growth factor 1 (IGF1) and osteopontin (OPN, also named SPP1), two factors known to have anti-apoptotic, proliferative, and pro-invasive activity in melanoma [34], [35].