Intracellular expression of IRF9-S1 or IRF9-S2C induced HLA-1 surface expression in the R15-3 cells. S9-13 and R15-3 cells were transfected and cultured (-) and (+) IFN-α (1,000 IU/ml). After 48 hours, HLA-1 surface expression was quantified by flow cytometry. (A) Shows the HLA-1 surface expression in the IRF9-Stat fusion transfected R15-3 cells. The red cell population represents IFN-α naïve cells or untransfected cells and the blue cell population represents IFN-α treated or transfected cells. IRF9-S1C, IRF9-S2C, and IRF9-S1C plus IRF9-S2C transfected R15-3 cells demonstrated significant increases in HLA-1 surface expression. (B) Each value represents the mean fluorescence intensity from six experiments. The student's t-test was used to compare the fold increase of transfected R15-3 cells to untransfected R15-3 cells plus IFN-α. Asterisk (*) indicates transfected R15-3 cells with significantly different HLA-1 surface expression relative to untransfected R15-3 cells. Significance was considered at p-values < 0.05.