The report in this issue of the Journal of Lipid Research by Rueda et al. shows that the survival and viability of Tregs is improved by incubation with HDL. Previous research over the last 20 years had demonstrated that plasma HDL possessed anti-inflammatory properties (1–4). Much of the early work focused on HDL as a vehicle to carry oxidized lipid products to the liver for catabolism as well as to inhibit the oxidation of LDL. Because HDL was proposed to carry oxidized lipids for excretion, it was also suggested that HDL could go “bad,” or become pro-inflammatory if it was overloaded with oxidized products or if the particles were not removed by catabolism.