Some of these Wip1 targets and the subsequent biological consequences of their inactivation by Wip1 have been reviewed previously, including p38, p53, ATM, Chk1, Chk2, Mdm2 and UNG2 (25). However, since last reviewed, additional Wip1 targets have been identified. Therefore, the interaction of Wip1 with MdmX, gamma-H2AX, NF-kappaB, XPA, and XPC will be discussed below.