PI3 and ductal breast carcinoma in situ: Using the highly specific monoclonal antibody against elafin (Hycult Biotech, clone: TRAB/2 F) (Additional file 1: Figure S1A and Figure S1B ) [18], we subjected TMAs containing sections of normal breast tissue from reduction mammoplasty (n = 24), DCIS (n = 54), and invasive breast carcinoma (n = 793) to IHC analysis (Figure 1).