Whereas TA/FL isoforms are generally considered as tumor suppressors [37, 49, 50], their ΔN counterparts that are crucial to epidermis development (ΔN-p63, [12]) or neural development (ΔN-p73, [18]) have been shown to be oncogenic factors involved in the dominant-negative effect by some studies [20, 25, 51] but have also been shown to be transcriptionally active by others [52–55]. This evidence concerns the gene TP73 and neoplasm.