G6PD and susceptibility to pneumonia measurement: More importantly, a recent article by Youssef et al., who investigated a small series of normal and G6PD-deficient subjects with COVID-19, highlighted a reduced survival rate among G6PD-deficient patients compared to normal ones; the deficient patients also presented more severe pneumonia (lower ratio of partial pressure of oxygen/fraction of inspired, more days on mechanical ventilation, lower hematocrit, and hemoglobin levels) [186].