Polymorphisms of the sulfonylurea receptor 1-transient receptor potential melastatin 4 (Sur1-Trpm4) cation channel are also associated with the development of malignant cerebral edema after acute brain injury.290,291 Importantly, investigators have recently identified a 3p21.31 gene cluster as a genetic susceptibility locus in patients with COVID-19 with respiratory failure and confirmed a potential involvement of the ABO blood-group system.292,293. The gene discussed is ABCC8; the disease is COVID-19.