NOTCH1 and retroperitoneal neoplasm: Of these, a novel DCBLD1-ROS1 fusion was observed in three cases, while other fusions occurred once in six cases, and seven novel partners occurred in two retroperitoneal neoplasm patients (FRK-ROS1, VGLL2-ROS1), one gastric cancer patient (ARHGEF11-ROS1), one liver cancer patient (REV3L-ROS1), one liposarcoma patient (EPHA7-ROS1), one patient with epithelioid hemangioendothelioma (NOTCH1-ROS1), and one squamous cell carcinoma patient (CARD11-ROS1).