TP63,also named KET,P63,P73H,P73L and TP73L,belongs to the p53 family. It is a homologue of the tumor suppressor p53 and p73 genes. It is involved in malignancy acquisition and maintenance of cells. Unlike p53,the p63 gene encodes multiple isotypes with remarkably divergent abilities to transactivate p53 reporter genes and induce apoptosis. TP63 acts as a sequence specific DNA binding transcriptional activator or repressor. TP63 has 12 isoforms with MW 40kd(P40),50kd(P60),63kd(P63) and 73kd(P73L). It is Nuclear stain.