A recent finding that IL-21+ICOS+CXCR5−CD4+ T cells expand in the human blood and help antibody production after vaccination also supports the presence of CXCR5− Tfh cells57, although whether CXCR5− Tfh cells induced by infection are the same as those induced in autoimmunity remains unclear. This evidence concerns the gene IL21 and Autoimmunity.