Rank CU, et al. - Researchers determined the incidence of thromboembolism during treatment of Nordic/Baltic acute lymphoblastic leukemia (ALL) patients 1–45 years treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol (7/2008–4/2017). The reported 2.5-year cumulative incidence of thromboembolism was 7.9% and preemptive antithrombotic prophylaxis could be required in patients ≥10years. Age ≥10years had the largest absolute risk ratio in a multiple absolute risk regression model addressing three thromboembolism risk factors. Relative to children <10.0years, an increased hazard of pulmonary embolism was seen in patients 18.0–45.9years and an increased hazard of cerebral sinus venous thrombosis in patients 10.0–17.9years.