IRS4 and polycystic ovary syndrome: We next selected the four ovarian genes that were differentially expressed and methylated in the PAMH F3 offspring versus controls and investigated the expression of the human equivalent of those genes, ROBO-1, SORBS2, CDKN1A, and HDC as well as IGFBPL1 (encoding for insulin-like growth factor binding protein like 1) and IRS4 (encoding for insulin receptor substrate 4), which may be related to defects in insulin signaling in PCOS.