Background: p63 (also called KET, p51, p40, AIS, and p73L) (1) is a transcription factor that shares a significant amino acid identity with p53 and p73. p63 and p73 can both activate p53-responsive genes and induce apoptosis upon over- expression (2). p63 has an additional coding region in the C-termini (not found in p53) that can undergo complex alternative splicing giving rise to 3 splice forms (α,, β,, and γ,) (3). Additionally, two isoforms can be found, one containing the N-terminal transactivating domain (TA) or the (Δ,N) lacking TA (2). p63 plays a more fundamental role associated with development and differentiation. Mutations in p63, although not as common as p53, may result in the ADULT, AEC and ECC3 syndrome (4-5).