CELA1 and neoplasm: A cohort of BptfP+/+;Ela1-Myc (n=10), BptfP+/−;Ela1-Myc (n=5) and BptfP−/−;Ela1-Myc (n=8) mice was monitored weekly by ultrasound to determine tumour-free survival and animals were killed when tumour burden reached ethical end points or mice showed overt signs of morbidity.