Known representative genes were used to recognize cell identities (Figure 2B), including three subtypes of dendritic cells (DCs): cDC1 (BATE3, XCR1), cDC2 (CLEC10A, FCER1A), DC3 (LAMP3, CCR7); two types of tumor-associated macrophages (TAMs): SPP1+ TAM (SPP1, MRC1), CXCL9+ TAM (CXCL9); monocytes (FCN1); myeloid-derived suppressor cells (MDSCs) (S100A8, S100A9, IL1B); Langerhans cells (CD1A, CD207); proliferating cells (MKI67, TOP2A). The gene discussed is MPPE1; the disease is neoplasm.