CD8A and endometriosis: Moreover, Abramiuk et al. [28] showed the role of immunosuppressive mechanisms in the development of endometriosis-related infertility: CD4+ and CD8+ T lymphocytes negatively correlated with the percentage of NK and NKT-like cells (confirming previous findings [34]), while CD8+ T cells positively correlated with the percentage of CD4+CD25+Foxp3high Treg cells.