In a 2015 study on infertility of Iranian women in relation to the PON1 enzyme at the Isfahan University of Medical Sciences, Iran, which was performed on 55 women with endometriosis and 65 women with PCOS, it was shown that individuals with MM genotype might be predisposed to infertility, while heterozygous (LM) might contribute to protecting the individual against infertility (p < 0.05) (29). The gene discussed is PON1; the disease is endometriosis.