TNFRSF13B and autoimmune thrombocytopenic purpura: If subjects with a TACI variant are excluded, 35% of subjects with a known gene were noted to have autoimmunity, more similar to those for whom no gene was identified (at 32%) as illustrated (Figure 3) The autoimmune cytopenia (ITP or AIHA) resulted in splenectomy in 34 patients, and 7 of the 17 with a known gene, had a TACI variant.