In a sharp contrast to p53, p73 and p63 are rarely mutated in human cancers.23p73 and p63 encode two major isoforms such as transcriptionally active TA isoforms (TAp73 and TAp63) and N-terminally truncated ΔN ones (ΔNp73 and ΔNp63).24, 25 TA and ΔN isoforms are produced by alternative splicing and alternative promoter usage, respectively. Here, TP53 is linked to cancer.