PTGDR2 and endometriosis: Elevated levels of IL-33 in PF from severe endometriosis cases is well established (15); however, for the first time to our knowledge, we report that live CD45+Lin–CD127+CD294+ST2+ cells (ILC2s) were detected in the PF from patients with endometriosis (Figure 1A and Supplemental Figure 1, A–F; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.149699DS1).