NLRP3 and obesity due to melanocortin 4 receptor deficiency: In addition, the increased susceptibility to SARS-CoV-2 infection documented in obesity suggests an initial defect in the defense mechanisms, most likely caused by the aforementioned higher systemic metabolic inflammation, which is regulated by NLRP3 inflammasome as a master regulator of metaflammation with a pivotal role in obesity (23–25).