FCN1 and cancer: Functional enrichment and gene expression in scRNA-seq data from different solid tumor tissues found that FCN1+ TAMs may induce inflammation; SPP1+ TAMs are potentially involved in metastasis, angiogenesis, and cancer cell stem cell activation, whereas C1Q+ TAMs participate in immune regulation and suppression; And CCL18+ cells are terminal immunosuppressive macrophages that not only have a stronger immunosuppressive function but also enhance tumor metastasis.