Furthermore, CMPK2 could increase the local concentration of cytidine triphosphate (CTP) for viperin to use as substrate to enhance the production of 3′-deoxy-3′,4′-didehydro-CTP (ddhCTP), which is necessary for the antiviral function of viperin during viral infection and inhibited SARS-CoV-2 polymerase activity in Huh7-hACE2 cells (Minton, 2018; Rivera-Serrano et al., 2020; Wood et al., 2021). Here, CMPK2 is linked to viral infectious disease.