CYP3A4 and COVID-19: CYP3A4 rs35599367 was the major genetic determinant of COVID-19 severity as carriers of this polymorphism had higher risk of critical disease (OR = 6.538; 95% confidence interval = 1.19–35.914: p = 0.031) and needed intensive care unit treatment more frequently (OR = 10; 95% CI = 1.754–57.021: p = 0.01).