Our data demonstrate that human Treg function can be modulated by knocking out diverse cytokine receptor genes, such as IL2RA and IL6RA. Since Treg function is likely being affected by high IL-6 levels under inflammatory conditions such as in autoimmunity or infectious diseases like COVID-19 in vivo, CD126 might be a potential target to enhance Treg stability and function in pro-inflammatory environments. This evidence concerns the gene IL6 and COVID-19.