B. Tumour volume changes over time for Rosa26_Alkal2;Th-MYCN mice treated with lorlatinib (10 mg/kg; twice daily) or vehicle control. Tumour volume was measured by ultrasound on Day 0 and 7, and by direct measurement at Day 14. Day 0 (lorlatinib n=7, Ctrl n=6), Day 7 (lorlatinib n=2, Ctrl n=5) and Day 14 (lorlatinib n=7, Ctrl n=6). Data shown represents mean ± SD. **p<0.005; two-tailed unpaired student t-test. 