In addition, CTLA-4+T lymphocytes were negatively correlated with the percentage of NK and NKT-like cells in women with both endometriosis and infertility35, which indicate that immunologic mechanisms of associated infertility may differ between endoplasmic reticulum stress subtypes and endometriosis clinicopathologic types and degrees of clinical manifestations of endometriosis. Here, CTLA4 is linked to endometriosis.