To this end, in our current study, using SCENITH single-cell metabolomics to evaluate the bioenergetics flux of freshly isolated COVID-19+ PBMCs, we successfully elucidated a systematic metabolic reprogramming characterized by excessive glucose metabolism accompanied with impaired mitochondrial fitness, resulting in subsequent cellular exhaustion specific to CD8+TM and NKT cells. The gene discussed is CD8A; the disease is COVID-19.