MAPK3 and polycystic ovary syndrome: Akt and ERK1/2 participate in insulin [44] and MAPK signaling pathways (KEGG Pathway Database, http://www.genome.jp/kegg/); genetic variants of AKT2 have been associated with PCOS in humans [45], while altered expression of MAPK signaling pathway components has been demonstrated in PCOS cumulus cells [46].