ACTA1 and cancer: In peritoneal dissemination, the MMT is important in the cancer microenvironment.1, 2, 3 To assess whether the MMT is also observed in the cancer microenvironment in pleural dissemination, surgically resected pleural disseminated nodules of lung adenocarcinomas were studied (Figure 2A‐C) by double‐staining immunohistochemistry using calretinin, desmin, and αSMA.