TNF and type 2 diabetes mellitus: In one study, mice fed a high fat diet to generate the obese/type II diabetes mellitus (ob/t2d) phenotype showed considerably increased levels of tumor necrosis factors (TNFs) in the synovial fluid of the knee joint, and studies comparing ob/t2d with TNF knockout mice demonstrated that TNF species were linked to increased expression of MMP-1, MMP-13, and ADAMTS4—a mouse homologue of matrix metalloproteinases.