Response of normal bone marrow resident CD10⁺/CD19⁺ B-cell precursors to CpG ODN stimulation. Mononuclear cells isolated from bone marrow samples obtained from 3 nonleukemic children were incubated with or without CpG ODN 2006 for 72 hours and analyzed in the same way as described for ALL patient peripheral blood. ▦ indicates CD10⁺/CD19⁺ cells; ▪, CD19⁺ B cells. The cumulative results for 3 patients are shown, expressed as the mean change (± SE) in the percentage of positive cells in response to CpG stimulation. All unstimulated CD19⁺ B cells were CD40⁺, so the increase in CD40⁺ cells was not assessable (NA).