Interestingly, in patients with type 2 diabetes, serum HER-2 concentrations were positively associated with serum soluble tumor necrosis factor-α (TNF-α) receptor 1 [r = 0.65, p = 0.001, n = 21] and serum DLK-1 (r = 0.81, p = 0.007, n = 9) (data not shown). This evidence concerns the gene DLK1 and type 2 diabetes mellitus.