AICAR induces upregulation of the p53 and the cyclin dependent kinase inhibitor p27 in ALL cells. Western blot analyses of p53, p27, and p21 were done using cell extracts from CCRF-CEM, NALM6, REH, and SupB15 cells treated with the indicated concentrations of AICAR (0 – 2 mM) for 48 h. Equivalent amount of proteins (50 μg) were separated by SDS-PAGE and immunodetected with antibodies against p53, p27, and p21. Membranes were stripped and reprobed with anti-β-actin antibody to confirm equal amount of proteins loaded in all lanes. Density value of each band was normalized to their respective β-actin level and expressed relative to control (untreated). The data shown are representative of 3 experiments producing similar results.