MYH11 and ductal breast carcinoma in situ: In addition, when the pathologist evaluated DCIS samples, all DCIS samples were stained with a panel of myoepithelial markers (Calcium‐binding protein (Calponin), tumor protein P63 (P63), and smooth muscle myosin heavy chain (SMMHC)) immunostaining, and the results confirmed that the myoepithelium was intact (Figure S1C, Supporting Information).