CTSG and obesity due to melanocortin 4 receptor deficiency: In addition, neutrophils can release diversified granule proteins, such as neutrophil serine proteases (including NE, PRTN3 and Cathepsin G) and Lipocalin 2 (48), to promote the development of obesity, NAFLD and type 2 diabetes mellitus through insulin resistance and metabolic inflammation (49, 50).