LAUSR

The treatment of advanced melanoma has been dramatically improved by the introduction of immune checkpoint inhibitors (ICIs). Previous studies indicated that blockading anti-PD-1 antibodies is more effective than anti-CTLA-4 antibodies1 . However, the response to anti-PD-1 antibodies in cases of acral lentiginous melanoma (ALM) and mucosal melanoma (MCM), the common melanoma types in Asians, is poorer than in cutaneous melanoma (CM), the major type in Caucasians2 . Since PD-L1 expression is an important biomarker for predicting tumor responses to anti-PD-1 antibodies, we speculated that the low responses to anti-PD-1 antibodies in ALM and MCM may be due to lower PD-L1 expression compared to CM. This article is protected by copyright. All rights reserved.