The difference gene expressions in logFC ≥ 1.5 between the COVID-19 and control samples were CTSS, EEF1A1, FABP4, GOT2, HSP90AA1, MYH7, MYH9, MYL6, NPC2, PLIN2, PRKAB2, PSAP, RPS27A, and VIM (Figure 2C). Here, CTSS is linked to COVID-19.