In particular, kallistatin acts as a negative acute phase protein that rapidly reduces its expression after lipopolysaccharide-induced inflammation in the liver, contributing to the decreased levels of kallistatin observed in the serum/plasma of patients with inflammation-related conditions, such as obesity, inflammatory bowel disease, and septic syndrome46,48,49. This evidence concerns the gene SERPINA4 and obesity due to melanocortin 4 receptor deficiency.