GSTM1 and COVID-19: In a Chinese study comparing hematologic variables between critically ill COVID-19 and other COVID-19 patients not having required ICU, median [Hb] was normal at baseline in both groups, but the median [Hb] nadir was then lower in critically ill patients (11.1 g.dl–1 [10.2–11.9] vs. 13.6 g.dl–1 [12.7–15.1]) (Fan et al., 2020).