B2M and Insulin resistance: Importantly, multiple correlation analysis (Fig. 8d) revealed that B2m expression in SAT was positively associated with BMI, homeostatic model assessment of insulin resistance (HOMA-IR), adipocyte size, and triglyceride (TG) levels, as were the expression levels of inflammatory cytokine genes (Tnf, Il1b, Il6, and Ifng) and iron storage-related genes (Fth and Ftl).