Since both obesity and T2DM are pro-inflammatory states, we examined the expression of several M1 phenotype markers in PBMC of lean, obese, T2DM, and T2DM on Metformin, including CD86, CD11c, CD169, IL-6, TNFα, iNOS, and CD36. Here, SIGLEC1 is linked to obesity due to melanocortin 4 receptor deficiency.