PVR and mucosal melanoma: While acral and mucosal melanomas reportedly have a non-inflamed TME with less efficacy of ICIs,35–37 a Japanese prospective observational study has shown that anti-PD-1 mAb exhibits similar efficacy against these types.34 We analyzed our cohort according to the type and found that the OS of patients with acral or mucosal melanoma was slightly shorter than that of the others (online supplemental figure S5B), which is consistent with previous studies.35–37 Next, we stained the FFPE samples for CD8 and CD155 before ICI treatment (online supplemental figure S6A).