IDO1 and COVID-19: Our computational analysis of the PPI network identified several highly interacting genes such as ICAM1, PTGS2, CXCL10, ITGAL, NCAM1, SERPINE1, IDO1, LEPR, PTAFR, and PLA2G2A (Figure 4), which also showed a higher degree of functional similarity with ACE2 and TMPRSS2 (Figure 7) suggesting a potential direct or indirect interaction with the COVID-19 spike protein (Cuperlovic-Culf et al., 2021).