ACSL4 and COVID-19: Several studies showed that increased serum hepcidin correlated with the severity of COVID-19.244,247 In addition, the scRNA-seq data of PBMC, T cells, and B cells from COVID-19 patients revealed that ferroptosis-related genes (including GPX4, FTH1, FTL, and SAT1) were increased in the acute phase and decreased in the recovery phase.55 Besides, SARS-CoV-2 was reported to downregulate the GPX4 mRNA level in infected Vero E6 cells.248 The induction of ferroptosis by SARS-CoV-2 could be reversed through two ACSL4 inhibitors in vitro.249 The ferroptosis triggered by SARS-CoV-2 is shown in Fig. 5.