PTPRC and neoplasm: An FAP+, platelet‐derived growth factor receptor (PDGFR)α+, PDGFRβ+, CD45−, EpCAM−, CD31− CAF population isolated from mouse lung and melanoma tumours inhibit T‐cell function via programmed death ligands 1 and 2 (PD‐L1 and PD‐L2), which bind to the programmed death 1 receptor (PD‐1) on T cells.10, 11