TACSTD2 and ductal breast carcinoma in situ: Expression of marker genes CEACAM6, SERPINA3, AGR3, and TACSTD2 for DCIS and ABCC11, FASN, CTTN, and SQLE for IDC (Supplementary Fig. S1A and B) identified DCIS and IDC regions in the tissue image plot (Fig. 6C).