To determine putative causal genes, a recent COVID-19 GWAS additionally conducted Mendelian randomization (MR) and transcriptome-wide association study (TWAS), utilizing information from expression quantitative trait loci (eQTLs) datasets in lung tissues and whole blood (GTEx project), and identified significant associations with the expression of seven genes (IFNAR2, TYK2 from MR analysis, and CCR2, CCR3, CXCR6, MAT2B, OAS3 from TWAS analysis)7. The gene discussed is CXCR6; the disease is COVID-19.