Moreover, the pathway of antigen processing and presentation (Hspa8, Hsp90ab1, H2–K1, Calr, Ifi30, Hsp90aa1) was enriched by the up-regulated genes in the B cells of T2D mice, which is associated with B cell activation (Fig. 5F; Fig. S7). This evidence concerns the gene CALR and type 2 diabetes mellitus.