Western blot of protein lysates from 8 MCL cell lines. The same blot has been probed with an antibody against an epitope lying between residues 2410 and 2460 of C-terminal NOTCH1 (sc-6014-R; top panel), an antibody against the Val1744 residue of active intracellular NOTCH1 (middle panel), and an antibody against β-actin (bottom panel). We used the T-ALL cell line HPB-ALL as a positive control. C-N indicates C-terminal NOTCH1; and ICN, intracellular NOTCH1.