Because overexpression of c-Fos induces apoptosis in human colorectal carcinoma cells [17], we focused on the c-Fos and FosB genes, which were conspicuously up-regulated in PC-3 and DU-145, but were weakly up-regulated in TIG-1 and even less so in LNCaP (S1 Table; pink and turquoise arrows in S2 Fig). This evidence concerns the gene FOSB and colorectal carcinoma.