Fetuin-B, which is secreted from the liver, is the second member of the cystatin superfamily of cysteine protease inhibitors.[5,6] Fetuin-B shares some similarity in functional analysis with fetuin-A, which has been found to cause insulin resistance by activating Toll-like receptors and inducing inflammatory signaling.[6–8] Meex et al[9] recently reported that fetuin-B was increased in humans with liver steatosis and patients with type 2 diabetes, impaired insulin action in myotubes and hepatocytes, and caused glucose intolerance in mice. Here, FETUB is linked to type 2 diabetes mellitus.