In this study, we report for the first time that (i) Yap signaling is enhanced in LV from patients with non-ischemic HF, (ii) Yap is induced in human adult cardiac fibroblasts by the pro-proliferative pro-fibrotic TGFβ/hypoxia exposure and (iii) silencing Yap expression inhibits cardiac fibroblast proliferation potentially via down-regulation of Akt signaling but, (iv) without affecting mTORC1 signaling. Here, AKT1 is linked to hydrops fetalis.