MRGPRF and cancer: GPCRs are membrane embedded receptors, regulating pivotal biological and pathological functions, which have emerged as valuable anti-cancer drug targets,47 and a myriad of mutations in multiple GPCRs, including melanocortin type 1 receptor and Wnt/frizzled receptor, have been demonstrated to be involved in melanoma progression.48 In this study, we provided evidence showing that MrgprF overexpression inhibited, while its knockdown promoted, tumor cell proliferation and migration in vitro, and xenograft tumor growth and metastasis in vivo, respectively.