Using TEQUILA-seq data, we identified numerous novel aberrant transcript isoforms in extensively studied cancer genes, such as NOTCH1 and RB1. A novel aberrant transcript isoform of NOTCH1 (ESPRESSO:chr9:9147:301) was found as the predominant transcript isoform in the MDA-MB-157 cell line. The gene discussed is NOTCH1; the disease is cancer.