CD4 and endometriosis: When comparing the menstrual phase and iNKT subtypes, the number of CD4+ iNKT cells expressing CD25 in the proliferative phase was increased in the endometriosis group compared with the control group (44.6 [0–60] vs. 33.2 [0–58.6]; p = 0.022) (Table 3; Fig. 4A).