The current findings migh have therapeutic implications: (1) the consistent lack of PD-L1 on tumor cells and tumor infiltrating immune cells, and the paucity of PD1+ cells in the TME of all our RMS cases (n = 39) (in agreement with previous studies33,60), makes the random targeting of this immune checkpoint unlikely to be successful, while specific targeting may eventually be effective in the small, previously reported RMS subset with a PD-L1high immunophenotype45,61. Here, CD274 is linked to neoplasm.