Figure 2. p53 target genes: p21, PUMA and MDM2 are expressed in PHA-activated T cells. T cells were isolated from peripheral blood of healthy donors and were cultured in medium with or without PHA (1 µg/ml) for the indicated time periods. p21, PUMA, MDM-2, p53 and phosphorylated p53 (Ser-15) expression was detected by immunoblots.