NLRP3 and obesity due to melanocortin 4 receptor deficiency: In obese individuals, the innate immune system might be already in a “primed state” due to chronic low-grade inflammation and this could promote an hyperinflammatory response (137, 138); under this scenario, we wonder if trained immunity mediated by NLRP3 in obese conditions to severe outcomes in COVID-19 patients, or normal weight patients infected by SARS-CoV-2 are developing trained immunity that accelerates and trigger short-term development of degenerative chronic comorbidities such as atherosclerosis, diabetes, osteoarthritis, gout, autoimmune diseases, and even obesity itself.