Both IL2 and TNF are known agonists for Treg expansion but the addition of TNFR2 agonistic antibodies in normal subjects results in selective expansion of the most potent Tregs.8 In T1D the percentage of Tregs, defined as CD4+Foxp3+CD127− cells, increased with 48 h of culture from a baseline with IL2 alone of 11.6±0.4% to a baseline of Tregs with TNF and IL2 to 13.6±0.37% and to a Treg-expanded population of 16.3±0.61% with a TNFR2 agonist with IL2. The gene discussed is TNFRSF1B; the disease is type 1 diabetes mellitus.