Regulation of MSX2 expression. MOLT-4 cells were treated for 16 h with 20 ng/ml IL7, TGFbeta, or BMP4, respectively. Subsequent expression of MSX2 was quantified by real-time PCR. In comparison to untreated control cells (set to 1) the level of MSX2 changed about 7-, 3- or 0.5-fold, indicating regulation by these thymic factors. Standard deviations are indicated by bars.