Apart from CK8/18, earlier reports described loss of CK7 and acquisition of CK20 in colorectal carcinoma (Park et al, 2002), acquisition of CK7, and loss of CK20 in gastric carcinoma (Park et al, 2002; Kim et al, 2004), and acquisition of CK1, 5, 6, 8, 19 in squamous cell carcinoma (Xu et al, 1995; Chu and Weiss, 2002a, 2002b; Ikeda et al, 2008). This evidence concerns the gene KRT7 and squamous cell carcinoma.