Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine with critical pathological roles in many disease, including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease and certain malignancies. While has been reported to have myriad functions, its primary function and mechanism of action are still not well understood. Moreover, while MIF clearly acts as a secreted factor, it also has intracellular roles potentially independent of its cytokine activity, including a direct role in facilitating NLRP3 inflammasome activation. A second MIF family member, D-dopachrome tautomerase (D-DT) shares structural homology to MIF and has been reported to have similar functions in the context of inflammatory responses. However, we have reported significant differences in serum levels of MIF and D-DT in patients with systemic sclerosis (SSc, scleroderma) and SLE. To further investigate the role of D-DT in inflammation, we have created Ddt-/- and Mif/Ddt-/- mice. These mice do not display any significant phenotypic differences, compared to wilt type and Mif-/- mice. Moreover, in contrast to Mif-/- macrophages and dendritic cells, which show decreased NLRP3 activation, these responses are unaffected in Ddt-/- cells. Similarly, while multiple small molecule MIF inhibitors abrogate NLRP3 activation in macrophages, the D-DT inhibitor 4-CPPC had no effect. Other cytokines were also inhibited by MIF antagonists, including IL-1α, TNF and IL-10, while 4-CPPC affected only IL-1α release. Our data suggest that MIF and D-DT may have different roles to play in inflammation and immune cell responses to infectious and inflammatory stimuli. These data take us closer to understanding how MIF and D-DT influence pathology in inflammatory diseases, potentially informing future targeting strategies.