Importantly, tumors from MUC15‐overexpressing cells showed decreased YAP nuclear localization (Figure S17d,e, Supporting Information) and reduced α‐SMA expression (Figure 6i; Figure S17e, Supporting Information), indicating that MUC15 regulates both direct metastasis and microenvironment remodeling through tumor cell‐PSC interactions. This evidence concerns the gene ACTA1 and neoplasm.