To compare the S100A6 staining pattern with that of cytokeratin 5 and cytokeratin 18, tissues arranged in a TMA, comprising of 19 cases of matched adenocarcinoma, benign epithelium and benign stroma were serially cut and immunostained for cytokeratin 5 (a marker of prostate basal cells), or cytokeratin 18 (a marker for benign luminal cells), which is also expressed in malignant cells (Freeman et al, 2002). Here, KRT18 is linked to adenocarcinoma.