β2-microglobulin
noun
β2-mi·cro·glob·u·lin
| \ ˌbāt-ə-ˌtü-ˌmī-krō-ˈgläb-yə-lən, chiefly British ˌbē-tə-
\
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Medical Definition of β2-microglobulin
: a beta globulin of low molecular weight that is present at a low level in plasma, is normally excreted in the urine, is homologous in structure to part of an antibody, comprises the light chain in certain histocompatibility antigens, and occurs at elevated levels in blood serum or urine in some pathological conditions (as tubulointerstitial disease)