Self-reactivity of recombinant FL Igs. Expressed Igs cloned from FL B cells were tested for self-reactivity by an indirect IFA on HEp-2 cells. (A) Summary of the frequency of self-reactive tumor Igs and the cellular localization of recognized antigens. The number of Igs tested is indicated in the center of the pie chart. (B) Examples of HEp-2 IFA staining patterns. Staining patterns of reactive Igs were confirmed in at least 2 independent experiments. Bars represent 25 μm.