INS and posterior cortical atrophy: It has been demonstrated that IGF2 and insulin stimulate steroidogenesis in PCa cells (van der Veeken et al. 2009, Lubik et al. 2011, 2013) while EGF signaling has been shown to stimulate steroidogenesis in Leydig tumor cells (Cameron et al. 1996, Manna et al. 2002, Shiraishi & Ascoli 2006).