Other studies with smaller patient cohorts have also reported an association between GDF-15 and COVID-19 severity, with dynamic changes in GDF-15 being closely associated with disease progression; in addition, a significant increase in GDF-15 among patients with COVID-19-related ARDS treated in the ICU compared to healthy controls was reported, with rising GDF-15 levels among non-survivors and decreasing levels among survivors [111,112,113,114]. This evidence concerns the gene GDF15 and COVID-19.