GPR68 and cancer: Similarly, we used immunohistochemistry (IHC) to quantitate populations of T-cells (CD3), macrophages (Iba-1), vasculature (CD31), fibroblasts (SMA) and proliferative cancer cells (Ki67) in tumors excised from Ogr1 KO mice or WT littermate controls and saw no significant differences in any of these populations by IHC (Supplementary Figure 5).