F2R and gastric cancer: Evidence for functional roles in cancer cells of GPCRs that are highly expressed and overexpressed in solid tumors and cancer cells include findings for PAR1/F2R in BRCA [25], gastric cancer [26], colon cancer [27], and melanoma [28] cells and for PAR2/F2RL1 in melanoma [28], BRCA [29], and colon cancer cells [30].