GPR91 expression was significantly associated with infiltration by activated CD8+ T cells, effector memory CD8+ T cells, activated CD4+ T cells, effector memory CD4+ T cells, Tregs, NK cells, neutrophils, macrophages, activated dendritic cells and B cells, and myeloid-derived suppressor cells in ovarian cancer [29,78]. The gene discussed is CD4; the disease is ovarian carcinoma.