TP53 and cholangiocarcinoma: The expression of Δ133p53 in cholangiocarcinoma correlated with poor clinical outcomes.[22] In contrast, overexpression of p53β and p53γ was correlated with improved responses to chemotherapy in AML.[23] In SCCHNs, elevated levels of the p53β isoform were found in a large number of samples.[24] In a study on melanoma, elevated levels of mRNA for p53β and Δ40p53 were detected in tumor cells but not in melanocytes or fibroblasts.[25] The expression patterns of p53 isoforms in the various tumors mentioned above are summarized in Table 1.