At a cellular level, data are conflicting about the potential predisposition of impaired O2 transport during COVID-19 (Park et al., 2020; Thomas et al., 2020); but, to date, there is no biological evidence to support the hypothesis of Wenzhong and Hualan that SARS-CoV-2 could be responsible for a clinically significant alteration of Hb affinity for O2 (Wenzhong and Hualan, 2020). Here, GSTM1 is linked to COVID-19.