CD274 and neoplasm: Kosemehmetoglu K et al reported a negative PD-L1 expression in MFS.[10] On the contrary, Jan Budczies et al demonstrated PD-L1 copy number gains were most prevalent in MFS compared with other subtypes.[11] In our case, 40% to 50% of tumor cells were stained positively by immunohistochemistry and a partial remission was observed.