Nuclear run-on analyses of IL-15 transcription in cord (CB) versus adult (APB) MNCs stimulated with LPS (10 μg/mL for 12 hours). Equivalent amounts of radioactive labeled RNA were hybridized to filters containing the indicated target DNA. Results shown are representative of three different experiments. US, unstimulated; S, stimulated; pUC 18, control vector; GAPDH, 775-bp Pst I/Xba I fragment from phc GAP; IL-15, 480-bp cDNA (CB 20- ± 2.5-fold v APB 22- ± 1.7-fold, P = NS, n = 3).