PTGDR2 and neoplasm: The endpoint biodistribution of [18F]MK-7246 in BALB/C nu/nu mice with a tumor developed from CHO-K1 cells expressing GPR44 displayed a significantly higher radioactive signal uptake in the tumor area compared to tumors developed from the implantation of non-transfected CHO-K1 (**** p < 0.0001) (Figure 9B).