DPP9 and COVID-19: The strongest association was found on chromosome 3 (rs73064425, closest to LZTFL1), but several other loci were found significantly associated with critical illness in COVID-19, such as those in the proximity to genes OAS1, OAS2, OAS3, TYK2, DPP9, and IFNAR2. In addition, it was found that IFNAR2 underexpression, as well as TYK2 overexpression are associated with critical illness, just like the differential expression in lung tissue of CCR2, CCR3, CXCR6, and MTA2B in critical disease (Pairo-Castineira et al., 2021).