CD81 and neoplasm: Furthermore, the mature TAM-related genes, such as CD206, CD81 (marker of macrophage M2), TSPO, HLA-DRA, IRF (marker of macrophage M1), and METTL14 (C1q+), were mainly expressed in TAMMC0 and TAMMC2 (the expression in TAMMC0 was higher than that in TAMMC2), but almost silenced in TAMMC1 (Figure 1C), indicating TAMMC0 as the mature TAM, TAMMC1 as the early tumor-associated monocytes (TAM-M0), and TAMMC2 as the transforming TAM-M0 from monocytes to macrophages.