For many genes (e.g., OAS1, IL10RB, DTX1, DONSON, CCR9, FYCO1, ACBD4, ARL17A, LRRC37A2, NSF, NXPE3), our TWAS and colocalization analysis using immune cell eQTLs (DICE dataset) provide the first evidence that their expression in specific immune cell types is likely to be causally linked to COVID-19 severity or susceptibility (Table 1). The gene discussed is ARL17A; the disease is COVID-19.