C1QC and breast cancer: Furthermore, FOLR2+tissue-resident macrophages have been identified in BC for their promoting effects on CD8+T cell infiltration.372 In CRC, scientists identified that FCN1+monocyte-like cells enriched in tumor tissues are the precursors of many tissue-resident macrophages, which finally develop into C1QC+ and SPP1+TAMs.326 C1QC+TAMs are highly related to IL1B+tissue-resident macrophage, and they perform cellular phagocytosis and antigen presentation.