PDCD1 and endometriosis: Similarly, we observed a higher CD8+/PD-1 : CD8+/PD-L1+ T cell ratio (8.11 ± 5.71, median 6.95, Min–Max 1.9–24.2) compared with other endometriosis patients (4.46 ± 2.84, median 4.09, Min–Max 1.5–10.6) (p = 0.047).