AG-490 inhibits IL-4 messenger RNA (mRNA) expression.

Results of RNase protection assay analysis of IL-4 mRNA isolated from AG-490 (100 μmol/L)–treated or DMSO-treated D10 cells are shown. The mRNA was isolated and examined for expression of murine IL-4 orL32 and GAPDH control genes by using a phosphorus 33 (³³P)–labeled probe. Densitometric analysis of IL-4 RNA message compared with L32/GAPDH indicated a greater than 79% reduction in the AG-490–treated samples (n = 3).