Transposon vectors expressing any gene-of-interest can be rapidly generated by the GateWay cloning system (Life Technologies). Plasmid vectors transiently expressing SB and transposon vectors expressing luciferase and any oncogene are complexed with polyethylenimine (PEI/DNA) delivered by intracranial injection into 1-day old perinatal mice. Stable oncogene integration by SB and expression can result in tumor growth, which can be monitored by luciferase imaging. CAGGS, cytomegalovirus early enhancer element and chicken beta-actin promoter; cargo, any DNA sequence-of-interest; pA, polyadenylation sequence; attB1 and attB2, GateWay flanking sequences after LR clonase reaction; PGK, phosphoglycerate kinase 1 promoter; SB, SleepingBeauty transposase enzyme; Luc, firefly luciferase reporter gene; Red arrowheads, SB inverted repeat/direct terminal repeat sequences.