IGF1 and prostate neoplasm: Analyses of human prostate tumor specimens suggest that PI3K/AKT and MEK/ERK signaling pathways are frequently activated by IGF-1, ErbB2, and VEGF in prostate tumors [13, 14, 15], via the phosphorylation, subsequent activation of NF-κB, Bcl2 protein, and deactivation of p21 and Bad protein.