Different from what is described above in pancreatic acini with PAK2 [10], endothelin did not activate group I PAKs in myocytes [93]; group I PAKs mediated IGF-1 and insulin signaling in mesothelial cells [115] and in mouse endocrine L cells [116], respectively; HGF regulated PAK1/PAK2 in prostate cancer [117] and epithelial cells [112,118]; and PKA activation was required for PAK activation by other GPCRs [94]. This evidence concerns the gene PAK2 and prostate cancer.