Regulation and function of the p53-related proteins: same family, different rules.

The tumour-suppressor protein p53 has recently been shown to belong to a family that includes two structurally related proteins, p63 and p73. Although all three proteins share similar transcriptional functions and the ability to induce apoptosis, each of them appears to play a distinct role in development and tumour suppression. In order for cell division to occur, the antiproliferative activities of these proteins must be tightly controlled, and exciting advances have been made in our understanding of the pathways involved in regulating p53 activity.