All of the following are tumor markers except

Ref Robbins 8/e p327 Beta2 microglobulin and not beta macroglobulin may be used as a tumor marker b2 microglobulin also known as B2M is a component of MHC class I molecules, MHC class I molecules have a1, a2, and a3 proteins which are present on all nucleated cells (excludes red blood cells). In humans, the b2 microglobulin protein is encoded by the B2M gene Low levels of b2 microglobulin can indicate non-progression of HIV. Levels of b2 microglobulin can be elevated in multiple myeloma and lymphoma, though in these cases primary amyloidosis (amyloid light chain) and secondary amyloidosis (amyloid associated protein) are more common. The normal value of b2 microglobulin is <2 mg/L. However, with respect to multiple myeloma, the levels of b2microglobulin may also be at the other end of the spectrum. Diagnostic testing for multiple myeloma includes obtaining the b2microglobulin level, for this level is an impoant prognostic indicator. As of 2011 A patient with a level <4 mg/L is expected to have a median survival of 43 months, while one with a level >4 mg/L has a median survival of only 12 months. b2 microglobulin levels cannot, however, distinguish between monoclonal gammopathy of undetermined significance (MGUS), which has a better prognosis, and smouldering (low grade) myeloma. Loss-of-function mutations in this gene have been repoed in cancer patients unresponsive to immunotherapies