TGFA and plasma cell myeloma: Interestingly, and in line with our data, whereas blood TGF-α levels were more than three times lower in patients with multiple myeloma (1.4 pg/mL) than in healthy controls (5.4 pg/mL), bone marrow TGF-α levels were higher in patients with multiple myeloma (44.7 pg/mL) than in healthy controls (28.9 mg/mL), although these findings did not achieve formal statistical significance (31).