SLC6A20 and COVID-19: First of all, we identified that both studied polymorphic variants located in the SLC6A20-LZTFL1 region are associated with COVID-19: rs17713054 SLC6A20-LZTFL1 (risk allele A) increases the risk of severe COVID-19 regardless of sex and age; however, this risk can be modified by smoking status, intake of fresh fruit and vegetables, and higher levels of physical activity.