OXSR1 is a serine/threonine kinase that functions as a key effector in the WNK signaling cascade, regulating ion homeostasis, osmotic stress responses, and blood pressure control 1. As a downstream target of WNK kinases (WNK1-4), OXSR1 recognizes RFXV motif-containing proteins and phosphorylates ion cotransporters including NKCC1/2, NCC, and KCC2/3, thereby modulating their activity to regulate cellular ion balance and volume homeostasis 2. In the kidney, OXSR1 mediates NaCl reabsorption in the distal convoluted tubule through NCC phosphorylation downstream of WNK4 3. Beyond ionic regulation, OXSR1 promotes angiogenesis in endothelial cells and regulates inward rectifier potassium channel localization 4. Recent studies reveal OXSR1's involvement in diverse pathological conditions: it contributes to sepsis-induced acute kidney injury through inflammatory and apoptotic pathways 56, supports acute myeloid leukemia progression via mTORC1 signaling and amino acid transport 7, and promotes hepatocellular carcinoma development through epithelial-mesenchymal transition 8. Additionally, OXSR1 acts downstream of the mechanosensitive Piezo1 channel in Ca²⁺-dependent WNK1 activation 1. These findings establish OXSR1 as a multifunctional hub integrating osmotic sensing with disease pathogenesis.