Role of SOX4 in ATL cell growth. (A) Effect of siRNA knockdown on SOX4 expression. Two ATL cell lines (HUT102 and ST1) and Raji were transfected with control siRNA or SOX4 siRNA. After 48 hours, total RNA samples were prepared, and quantitative real-time PCR was performed. Data are shown as mean ± SEM of 3 separate experiments. *P < .05. (B) Effect of SOX4 siRNA on cell growth. Two ATL cell lines (HUT102 and ST1) and Raji were transfected with control siRNA or SOX4 siRNA and cultured in a 96-well plate at 0.5 × 10⁴ cells per well. At indicated time points, viable cells were counted on FACSCalibur by gating out cells stained with propidium iodide. Data are shown as mean ± SEM of 3 separate experiments. *P < .05; **P < .01. (C) Effect of SOX4 overexpression on cell growth. HUT102 cells were transfected with the control EGFP vector or pSOX4-EGFP. After 48 hours, cells expressing EGFP were sorted and cultured in a 96-well plate at 0.5 × 10⁴ cells per well. At indicated time points, viable cells were counted on FACSCalibur by gating out dead cells stained with propidium iodide. Data are presented as mean ± SEM of 3 separate experiments. *P < .05.