Folliculogenesis is negatively impacted by the hyperandrogenic and insulin-resistant environment typical of PCOS, which is common across all phenotypes but commonly worsened in instances of obesity, by disrupting intra-ovarian signalling pathways, including as PI3K/AKT, ERK1/2, and TGF-β/SMAD pathways [24]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.