Cancer: a new role for non-canonical Hippo signaling.

The molecular mechanisms governing self-renewal and differentiation of the mammary epithelium are incompletely defined; a better understanding of the events implicated in the specification and expansion of luminal progenitors is of particular importance as many breast cancers originate from their transformation. Britschgi et al. found that, in addition to phosphorylating and inactivating YAP, LATS functions as a scaffold to facilitate estrogen receptor-α ubiquitylation by the E3 ligase CRL4 and consequently suppresses luminal progenitor specification and expansion.