Similarly, combinations of Fgfr2FL with Myc, Fgf3 and/or Ccnd1 cDNAs into single lentiviral constructs cooperatively shortened tumour onset after intraductal delivery, with the latencies of the Fgfr2FL-T2A-Myc and Fgfr2FL-T2A-Fgf3-P2A-Ccnd1 combinations matching Fgfr2ΔE18 single-driver latency. The gene discussed is FGF3; the disease is neoplasm.