PIEZO1 and hydrops fetalis: The reduced stress fiber formation and nuclear localization of YAP1 in both HF-SCs and HG progenitors in Piezo1 iKO skin suggests perturbed force generation and mechanical sensing in these compartments upon the loss of Piezo1. It was recently demonstrated that quantitative measurement of F-actin signal intensity and nuclear YAP1 can distinguish the transition from quiescent telogen to active anagen phase (14).