Similar to Tfh-like cells, which were found in SLE and other autoimmune diseases (Horiuchi and Ueno, 2018; Hutloff, 2018; Rao, 2018; Vu Van et al., 2016), the super-functional subset delivers effective B-cell help for IgG production in an IL-21- and CD40L-dependent manner. Here, IL21 is linked to systemic lupus erythematosus.