CD19 and systemic sclerosis: Almost all of these cells were CD38-CD95+ cells (Figure 2—figure supplement 2), and expression of co-stimulatory molecules (CD80/86, ICOSL, and CD40) in topo I-non-reactive B cells and topo I-reactive B cells (topo I-PE+Topo I-APC+CD19+CD27+) with low or high affinity for topo I in anti-topo I antibody-positive SSc patients was elevated (Figure 2—figure supplement 3).