The Ever-Lengthening Arm of p53

p53 is a pivotal bulwark against cancer, but exactly how it suppresses tumors remains elusive, in part because it modulates such diverse biological processes via so many downstream pathways. In a recent issue of Cell, Godar et al. (2008) now identify another string to p53ʹs anticancer bow—repression of the CD44 cell-surface glycoproteins that coordinate many attributes of tumor progression.