To test if these events occurred in Id1 transgenic T cell lymphomas, we determined levels of Notch1 transcripts by using PCR primers specific for exons 5–6 and exons 33–34 to amplify Notch1 transcripts via the 5′ and 3′ ends, respectively (Fig. 5A). The gene discussed is NOTCH1; the disease is T-cell non-Hodgkin lymphoma.