TF and systemic lupus erythematosus: Two interrelated populations of circulating B cells present in SLE patients, namely the CD11chi B cells, which are also called age associated B cells (ABCs) (Karnell et al., 2017; Rubtsov et al., 2017), and the IgDnegCD27neg B double negative (BDN) B cells, which are often referred to as ‘atypical’ memory B cells (Wei et al., 2007; Portugal et al., 2017), are reported to express the IFNγ-inducible TF T-bet.