MAP4K4 is a serine/threonine kinase functioning as a critical node in mechanotransduction and stress response pathways. Mechanistically, MAP4K4 acts downstream of the RAP2 GTPase to sense extracellular matrix stiffness and activate the Hippo pathway by phosphorylating LATS1/2, thereby suppressing YAP/TAZ-mediated proliferation 1. MAP4K4 also regulates JUN N-terminal kinase signaling and can restrain hyperactive RAS signaling during early development 2. Clinically, MAP4K4 dysfunction is associated with multiple disease states. Loss-of-function variants cause neurodevelopmental disorders and congenital anomalies 2. In metabolic disease, MAP4K4 downregulation in T cells promotes IL-6+ Th17 differentiation, contributing to type 2 diabetes pathogenesis 3. In cardiovascular conditions, MAP4K4 is upregulated in diabetic cardiomyopathy and promotes endothelial dysfunction through S-nitrosylation of Drp1 and ferroptosis activation 4. Similarly, in diabetic retinopathy, MAP4K4 overexpression in endothelial cells exacerbates microvascular injury via NF-κB pathway activation, with expression regulated by YTHDF2 5. Conversely, MAP4K4 inhibition with DMX-5804 reduces cardiomyocyte death from oxidative stress and ischemia-reperfusion injury 6, establishing MAP4K4 as a promising therapeutic target for cardiac and metabolic diseases.