UPK2 and carcinoma: Without doxycycline treatment (e.g., without FGFR3b-S243C expression), the triple transgenic mice bearing UPII-rtTA-M2, TRE-FGFR3b-S243C and UPII-SV40T transgenes exhibited high-grade carcinoma-in-situ lesions in the bladder (Fig. 5C), much like what was observed reproducibly in low-copied, UPII-SV40T single transgenic mice23, 24.