KRT5 and lung adenocarcinoma: For example, we noticed that CK5/6 expression was present in 2% of lung adenocarcinoma by using 1:25 dilution of D5/16B4 antibody (Boehringer-Mannheim) and Envision + biotin free detection system in Dako AutoStainer [16], but 39% by using the same 1:25 dilution of different D5/16B4 antibody (Dako) and Envision + HRP detection system in the same IHC stainer [12].