Furthermore, flow cytometry found that PD-L1 was expressed on most MPE/MA-cells (Fig. 1k), especially on CD45+ leukocytes, such as T cells, B cells, myeloid-derived suppressor cells (MDSCs) and tumor‐associated macrophages (Fig. 1l and Supplementary Fig. S1a, b). Here, PTPRC is linked to neoplasm.