Within the LHCGR window, SNPs in the 5’ and intron 1 regions of the LHCGR gene, surrounding the PCOS risk SNP rs13405728, were associated with methylation level of three CpG residues clustered in the STON1-GTF2A1L gene (S5 Table and Fig 3). This evidence concerns the gene STON1 and polycystic ovary syndrome.