Serum: elevated LDH, positive beta-2 glycoprotein, a polyclonal gammopathy with elevated gamma component, suspicious for multiple myeloma. Elevated methylenetetrahydrofolate reductase (MTHFR) C677T gene, weakly positive hexagonal phase lupus anticoagulant, reduced antithrombin and protein C activity, elevated factor VIII activity; CSF: normal. Here, MTHFR is linked to plasma cell myeloma.