PCYOX1 and COVID-19: PCYOX1 plays a key role in protein prenylationand in the releaseof hydrogen peroxide.126 Urine and serumPCYOX1 levels are negatively regulated in patients with severe andcritical COVID-19 (Shen_1 and Shu_1 data sets).102,107 Lower PCYOX1 levels in these patients may contribute to COVID-19-associatedliver dysfunction.40 Its high abundancein the COVID-19-positive cohort suggests potential protective effectsin low-severity cases.