TBX21 and systemic lupus erythematosus: Indeed, the frequency of B cells expressing CD11c+ in the absence of Tbet (CD19+CD11c + Tbet-), was substantially more frequent in SLE (median 15.21 %, 95%CI [13.04–19.00]) than in HD (10.28 %, 95%CI [8.63–11.15], p = 0.002).