PDCD1 and endometriosis: We also identified putative inhibitory interactions between endometriosis immune cells and ectopic FBs rather than eutopic FBs, including KLRB1, TIGIT, and PDCD1, which were highly expressed by NK and T cells, and potentially bind to CLEC2D, NECTIN3, and FAM3C, which were expressed by FBs (Fig. 8C).