Immunohistochemistry of tumor sections (Figure 7B) confirmed the western blot results by showing enhanced levels of E-cadherin and p27 in the Am580 responsive tumors and also revealed, that the RARα target gene involved in ATRA catabolism, cytosolic Cyp26A1, was strongly induced in these tumors compared to the Am580 nonresponsive and Myc-Ctrl tumors. This evidence concerns the gene CYP26A1 and neoplasm.