WNIN/GR-Ob (Ob-T2D) rats showed an increased expression of pro-inflammatory cytokines IL-1α, IL-1β, IFN-γ, IL-6, MCP-1, MIP-3A, CINC-2, CINC-3, GM-CSF, and TNF-α in their serum and adipocyte milieu, when compared to the WNIN/Control rats (Figs. 2f, 3a,b; Supplementary Fig. 2a–c). Here, CCL2 is linked to type 2 diabetes mellitus.