Endometriosis patients with adhesions presented statistically lower frequencies of CD8+/PD-L1+ T cells (1.35 ± 0.83, median 1.05%, Min–Max 0.5–3.6%) than in those from the other endometriosis groups (2.72 ± 1.95, median 2.13%, Min–Max 0.9–6.97%) (p = 0.036). The gene discussed is CD274; the disease is endometriosis.