The LNH-94 antibody reacts with human CD298, the β3 subunit of the Na+/K+ ATPase. The Na+/K+ ATPase is a 42 kDa type II transmembrane protein composed of four catalytic α subunits and three smaller glycosylated non-catalytic β subunits. The Na+/K+ ATPase is important for establishing electrochemical gradients and maintaining normal resting membrane potential by coupling ATP hydrolysis to the active transport of Na+ and K+. The β subunits have been reported to act as chaperones that stabilize the α subunits and occlude K+. CD298 has been used to identify metastatic human cancer cells in mouse xenograft models and has been reported to modulate aspects of immunity, including HIV production, and T cell and B cell activation. CD298 is found on leukocytes, platelets, and most other tissue types.