However, colocalization, defined as association with both traits through a single causal variant (PPH4 > 0.5) was only observed in 5 out of the 11 pairs: BGAT, KLC1, and MRVI1 with hospitalized COVID-19 and STAT3 with severe and hospitalized COVID-19, providing strong evidence of their causal role in COVID-19 progression. This evidence concerns the gene KLC1 and COVID-19.