ATP1A1 and COVID-19: In particular, the mean reduction in the expression of the ATP1A1 gene in PBMCs of COVID-19 with NTIS compared to that observed in COVID-19 patients without NTIS was more evident (64.5% reduction) and statistically significant (p < 0.0005) with respect to that observed in the expression of the ATP1B1 gene (15.2% reduction).