Over expression of A20 suppresses p53 protein. A, the immune blots indicate A20 levels in HEK293 cell extracts. Control: Naïve HEK293 cells. pA20 (or pcDNA3.1): HEK293 cells were transfected with A20 (or control) expression plasmid. The β-actin is an internal control. B, the bars indicate the levels of p53 in HEK293 cells (by ELISA). A20-ov-e: HEK293 cells with A20 over expression. *, p < 0.01, compared with naïve controls. C, the immune blots indicate the p53 levels in the cell extracts of HEK293 cells after treatment with exogenous A20 at the indicated doses (denoted below the blots) in the culture for 48 h. The data represent 3 separate experiments. The data represent 3 separate experiments.