They are highly heterogeneous and multifunctional,[30, 31, 32] but their origins are still largely unknown.[33] The present study is the first to investigate the implication of MMT in cancer, revealing a direct mechanism of TAM for promoting CAF generation using well‐established lineage tracing strategies.[6, 8, 9, 24, 36] In this study, we demonstrated the existence of MMT in cancer by identifying their co‐expression of TAM (CD68) and CAFs (α‐SMA) markers in the lung, kidney, and prostate cancers. This evidence concerns the gene ACTA1 and prostate cancer.