Thinking inside the box: endogenous α-anomeric lipid antigens.

The most powerful iNKT cell antigen is α-galactosylceramide (α-GalCer), derived from the marine sponge. However, α-anomeric glycolipids are thought to be absent in mammals. In this issue of Immunity , Kain et al., (2014) demonstrate the presence of mammalian α-linked glycosylceramides, such as α-GalCer.