HPRT1 and neoplasm: Median and range of the ΔNp63 mRNA/HGPRT mRNA ratio was 1.40 (1.37–1.55) for normal urothelium, 0.74 (0–1.65) for LPN tumour, 0.60 (0–1.67) for T1 tumour, and 0.00 (0–0.95) for muscle-invasive or metastatic carcinomas.