Expression of Egr-1 mRNA in FA-A lymphoblasts treated with UV and PMA. Control and FA-A cell lines were exposed to UV and left in culture for the indicated time intervals (A) or treated with PMA for 1 hour (B), and then total RNA was extracted and analyzed for the expression of Egr-1 by semiquantitative RT-PCR. GAPDH mRNA was used as an amplification control.