Another study by Maeda et al. [7] corroborated this, demonstrating higher levels of KIR2DL1 + NK cells among CD16 + NK cells in the endometriosis group compared with the control group; however, the results were only statistically significant in advanced endometriosis (24.3% ± 15.6% vs. 11.6% ± 6.8%, p = 0.008). Here, KIR2DL1 is linked to endometriosis.