Activation of Notch1 during Lmo2 tumorigenesis. Levels of NICD present in extracts of tumors from double-positive (DP), double-negative (DN), and single-positive (SP) T cells tumors from animals described in Figure 1B were assessed by immunoblotting using a rabbit monoclonal antibody to Notch1 cleaved at val1744 (D3B8; Cell Signaling Technology) at a dilution of 1:250. Jurkat cells were used as the positive control (+ve) and GPE-86 cells were used as the negative control (-ve). The Mouse NICD is smaller than the human form with a predicated molecular weight of 85kDa. β-actin was used as the loading control. The mouse number and tissue source (TH indicates thymus; BM, bone marrow) are shown for each lane.