Characterization of T-ALL cell lines with conditional PFKFB2-15A and -15B expression. CEM-PFKFB2-15A #D6 (Figure 2A) and CEM-PFKFB2-15B #66 (Figure 2B) cells expressing PFKFB2-15A and -15B in a doxycycline-dependent manner, respectively, were cultured in the presence of increasing concentration of doxycycline (Dox) for the indicated time and analysed for PFKFB2 expression (see Figures S2 and S3 for the corresponding data for the remaining 4 cell lines used in this study). mRNA expression was assessed by using quantitative real time RT-PCR targeting the exons-3/exon-4 boundary present in both splice variants. The data derive from 3 biological replicates analyzed in triplicate and expressed as -ΔCT (i.e., CT value of PFKFB2-15A minus CT value of TBP). PFKFB2 protein was detected by immunoblotting with antibodies against PFKFB2 and α-TUBULIN as loading control (right panels). Shown are representative examples of cells treated with the indicated amounts of doxycycline for 24 hours.