HLA-DPB1 and neoplasm: Because PD-L1 expression is the most important factor for predicting response to anti-PD-1 blockade therapy23, we investigated PD-L1 expression in SFTs, and found 13.74% (18/131) of SFTs had high PD-L1 expression in tumor cells and 10.69% (14/131) of SFTs had high PD-L1 expression in immune cells, especially in CD68+/ HLA-DPB1+/CD163+ macrophages (Fig. 3e, Supplementary Fig. 4a).