P57Kip2regulates T-cell development and lymphoma
In this issue of Blood, Matsumoto et al report that T cell-specific deletion of the cyclin-dependent kinase inhibitor p57Kip2(p57) in mice leads to a block in T-cell development as a result of hyperactivation of the E2F-p53 pathway and demonstrate that the loss of p57 accelerates lymphomagenesis in the absence of p53.