**3. The future players in DED**

Both novel techniques (single cell sequencing and massive flow cytometry) and the discovery of novel functions have allowed the better characterization of immune cell populations, revealing a wider diversity of lymphocyte subpopulations than previously thought. As an example, mucosal-residing ILCs have emerged as central early regulators in the immune response. In the case of inflammatory diseases, including DED, lymphocyte populations have specifically received more attention than others, which does not imply that the populations that we do not yet understand are less important. Notably, MAITs and ILCs are only beginning to arise as potential drivers in eye pathologies. Few studies have, for instance, shown that extremely low numbers of ILC2s reside in the mouse cornea and are recruited upon corneal epithelial injury, where they are required for cornea tissue repair [68]. Additional studies described that cells, presumably ILCs, can be isolated from human and mouse conjunctiva [69]. In eye pathologies, MAITs were reported to be increased in acute anterior uveitis [70] and ILCs played no role in ocular infection with herpes simplex virus (HSV)2 [71]. Thus, a role for MAITs and ILCs cannot be ruled out in DED, and future evidence will further our understanding of the expanding universe of lymphocytes in DED.
