For the purpose of presentation and discussion, the PCOS candidate genes were grouped based on their known basic functions; DNA/RNA regulation/processing (HMGA2, TOX3, GATA4, YAP1, ZBTB16, IRF1, NEIL2, RAD50, KRR1), cellular functions (RAB5B, ARL14EP, DENND1A, THADA, MAPRE1), enzymatic reactions (C9orf3/AOPEP, SUOX, SUMO1P1), cell surface receptors (ERBB3, ERBB4, PLGRKT), extracellular matrix regulation (FBN3), metabolism (INSR, FDFT1), and reproduction (FSHB, FSHR, LHCGR, AR, AMH). This evidence concerns the gene NEIL2 and polycystic ovary syndrome.