A20 transduced cells express surface TACI and bind ligand. (A) Representative flow cytometry results for the A20 parental cell line, A20 GFP, and A20 short, long, or nonsignaling S194X TACI–transduced cells showing similar TACI and GFP expression. TACI expression was also tested by ligand-binding assay and analyzed by flow cytometry. Numbers indicate percentage of positive cells. Plots are representative of 3 independent experiments. (B) TACI immunoblot from same cells expressing similar levels of TACI protein. hu, human.