Immunohistochemical analysis of paraffin embedded solid tumors (TOV1369, TOV2295(R), TOV3133D and TOV3133G) with keratin markers, p53 and HER20. Nuclei are counterstained with hematoxylin, and images are at x400 magnification. Positive staining was seen for all solid tumors for each keratin tested, and HER2. Note the lower expression detected for p53 in TOV3133D and TOV3133G. Note that the (t) designation denotes that the primary tumor tissue was investigated.