CFD and obesity due to melanocortin 4 receptor deficiency: Beyond its immunological functions, the adipsin/C3a axis is implicated in a range of physiological processes, including immune regulation, cell migration, insulin sensitivity, adipocyte differentiation, and the homing of hematopoietic stem cells (9).Serum adipsin levels in healthy individuals are in the range of 1-2 μg/mL (10), and while they are lower in conditions such as insulin resistance (11, 12), adipsin levels increase in obesity and other metabolic disorders, demonstrating the importance of this adipokine in both health and disease (13–16).