ROS1 and glioblastoma: Group 1 tumors harbor ALK/ROS1/NTRK/MET alterations (Figs. 1b, c; 2a), and are enriched for HGG (82.8%, 24/29, p < 0.0001, Fisher exact test, Fig. 4a), specifically glioblastomas (15/29), and younger infants (Table 1, median age at diagnosis 2.8 months, range 0–12 months) (examples of congenital tumors in Fig. 2c–e).