Interestingly, gene ontology analysis revealed that the upregulated differentially expressed genes (DEGs) of the in‐vivo‐generated MMTs (α‐SMA+ CD68+ cluster) from the macrophage‐lineage scRNA‐seq were strongly associated with protumoral functions including angiogenesis and collagen fibril organization (Figure4A,B; File S1, Supporting Information), which were absent in the DEGs of transforming growth factor beta1 (TGF‐β1)‐generated MMTs in our previous study in vitro[28](Figure S8, Supporting Information), suggesting a protumoral feature of the MMTs under cancer condition in vivo. This evidence concerns the gene ACTA1 and cancer.