||Mariani, L., Schulz, E. G., Lexberg, M. H., Helmstetter, C., Radbruch, A., Löhning, M., & Höfer, T. (2010). Short-term memory in gene induction reveals the regulatory principle behind stochastic IL-4 expression. Molecular systems biology, 6(1). p.2 right column 4th paragraphPubMed ID20393579
||P.2 right column 4th paragraph: "To analyze the kinetics of IL-4 induction, [researchers] measured mRNA, intracellular and secreted protein over 6h in the presence of the P/I [PMA and ionomycin] stimulus. IL-4 mRNA levels reached a peak after ~3h and dropped back to a low level within the next 3h (Figure 1B). Intracellular protein followed with a delay, reaching its maximum approximately at hour 4 (Figure 1B). IL-4 accumulation rate in the extracellular medium attained its maximum at the same time (Figure 1B, Supplementary Figure S2). Thus, the P/I stimulus induces rapid and transient IL-4 expression in a Th2 cell population."