APOE and Infertility: The research results presented above enable us to conclude that, while the ApoE genotype is not associated with the diagnosis of endometriosis, the patients with endometriosis and a minimum of one spontaneous pregnancy loss (SPL) were more likely to be ɛ2 carriers and less likely to be ɛ4 carriers, and an association may be also observed between ApoE allelic frequency and SPL in patients with endometriosis, which seems to be independent from infertility causes.