Expression analysis of primary T-ALL cells. Quantitative real-time expression analysis of NOTCH3 and HEY1, was performed in primary T-ALL cells by real-time PCR. Expression of TBP served as endogenous control. The figure indicates mean expression levels of analyzed probes. Bars show standard deviations. The significance of these data was calculated using the t-test with p = 0.03 (*) and p = 0.01 (**).