IL-4 present in human ovarian endometriomas can stimulate the proliferation of endometrial stromal cells (OuYang et al., 2008), while the CCL5/CCR5 axis may promote endometriosis progression via T-cell suppression and recruitment of CCR5+ myeloid-derived suppressor cells (Zeng et al., 2022). The gene discussed is IL4; the disease is endometriosis.