INSR and Hirsutism: In addition, SRD5A, a variant of the 5α-reductase type 1 gene responsible for hirsutism, as well as other genes related to metabolism, such as thyroid adenoma-associated (THADA) gene or the already mentioned INSR-insulin receptor gene, associated with insulin resistance PCOS in liver cells, fibroblasts, and skeletal muscle, including also insulin receptor substrate protein (IRS) [37,38].