The low anion gap.
D000136:Acid-Base Equilibrium; D000137:Acid-Base Imbalance / Q000378:metabolism*; D006801:Humans; D009101:Multiple Myeloma / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism; D012964:Sodium / Q000097:blood; D014883:Water-Electrolyte Imbalance / Q000378:metabolism
D012709:Serum Albumin; D012964:Sodium