Consistently, male db/db (leptin receptor deficiency) C57BLKS/J (BLKS) mice, the most widely used mouse model of T2DM, had a similar but more robust increase of serum heparin levels compared to littermates with one allele of mutant in leptin receptor (db/+; 1.48 ± 0.18 vs 3.28 ± 0.37; Figure 1A). This evidence concerns the gene LEPR and type 2 diabetes mellitus.