FXYD7 is a small single-span transmembrane protein that serves as a tissue-specific regulator of the sodium/potassium-transporting ATPase (Na+/K+-ATPase) 1. The protein associates with Na+/K+-ATPase and modulates its transport properties by reducing the apparent affinity for external K+, an effect that depends on the presence of external Na+ and voltage 2. FXYD7 is exclusively expressed in the brain, where this modulation of K+ affinity may be essential for proper neuronal excitability 2. Unlike other FXYD family members such as FXYD1 (phospholemman), FXYD7 can translocate to the cell surface independently of Na+/K+-ATPase coexpression 3. This membrane translocation requires O-glycosylation of at least two of three conserved threonine residues in its ectodomain, and mutations of these threonines to alanine result in protein retention in the endoplasmic reticulum and Golgi apparatus 3. FXYD7 represents part of a broader family of FXYD proteins that provide tissue-specific regulation of Na+/K+-ATPase activity, ensuring appropriate ion handling for specialized cellular functions 4. In disease contexts, FXYD7 has been identified as a potential biomarker in temporal lobe epilepsy and pediatric high-grade gliomas 56.