p63 (TA) is a member of the p53 family. This protein has multiple isoforms TA p63-alpha, -beta, -gamma, and deltaN p63-alpha, -beta, -gamma. The molecular weight of the TA p63 isoforms alpha=77 kD, beta=62 kD, and gamma=56 kD. This nuclear protein is essential for limb formation, epidermal morphogenesis, epithelial stem cell regeneration; deltaN isoforms are antagonistic to p53; TA isoforms can transactivate p53 targets. The p63 deltaN isoforms repress TA isoforms; mutant p53 abrogates p63 transactivation This protein interacts with p53, p73, and the various p63 TA- and deltaN isoforms. The Poly6189 antibody recognizes human p63 TA isoforms and has been shown to be useful for Western blotting.