Figure 6.

B cell analysis in peripheral blood of patients with cancer. Non-single events were excluded as described in Figure 1. (A) melanoma; (B) breast cancer; (C) brain cancer. B lymphocytes were identified using CD45 and CD19. Naïve and marginal zone B cells were identified based on their expression of IgD and CD27. Class unswitched memory B cells were identified as IgM+IgD+CD27+CD38–. IgM–IgD– B cell were separated into class-switched memory B cells based on expression of CD27 and lack of CD38. Plasmablasts were identified as CD27+CD38+. Range in frequency of cell subsets is shown in Table S6.