PCOS women carriers of the minor T allele at rs3962158 (Asp4Asp) in exon 1 of DNAJB1 had increased insulin (CC: 78.0 (92.4) vs. CT/TT: 108.0 (124.5) pmol/l; P = 0.0031); increased HOMA-IR (CC: 1.72 (1.96) vs. CT/TT: 2.34 (2.39); P = 0.006) and increased HOMA-%B (CC: 145.2 (99.2) vs. CT/TT: 177.2 (108.6); P = 0.004). The gene discussed is INS; the disease is polycystic ovary syndrome.