MBL2 gene polymorphisms[19] are thought to be associated with the severity of COVID-19 infection, and the presence of the B allele (rs1800450)[20] due to MBL deficiency is associated with poorer clinical presentation of patients, including the need for hospitalization and the need for ventilator use.[20] Certain genetic polymorphisms[21–23] in INFL4 may contribute to population susceptibility to COVID-19, but its association with disease severity still requires additional animal studies or clinical studies to reveal. The gene discussed is MBL2; the disease is hyperinsulinemic hypoglycemia, familial, 4.