Further studies are required to understand association of S. japonicum infection and CETP gene mutation based on genome-wide analysis for evolutional backgrounds of the human genes in certain regional or ethnic groups, like the recent findings of copy number variants in Melanesians selected from Denisovans and Neanderthals (Hsieh et al., 2019) or lack of inheritance from Neanderthals in East Asians of genetic risk factors for clinical severity of COVID-19 (Zeberg and Pääbo, 2020; Zeberg and Pääbo, 2021). Here, CETP is linked to COVID-19.