F-actin dynamics regulates mammalian organ growth and cell fate maintenance.

•Absence of CAPZ leads to increased cell contractility and tissue stiffness.•Loss of CAPZ leads to liver overgrowth, hepatocyte reprogramming and metabolic defects.•These phenotypes are due to YAP hyperactivation, and occur in parallel to LATS1/2.•ROCK inhibition rescues the effects of CAPZ inactivation.•Loss of CAPZ unveils the relevance of mechanical signals for tissue homeostasis.