The PTCH1 gene, located in chromosome region 9q22, is a candidate tumour-suppressor gene, as loss of heterozygosity on chromosome arm 9q occurs in more than 50% of TCC (Linnenbach et al, 1993; Habuchi et al, 1995; Hirao et al, 2005), and PTCH1 mRNA expression is low, compared with normal urothelium, in early-stage tumours exhibiting LOH in the 9q22 region (Aboulkassim et al, 2003; Hirao et al, 2005). This evidence concerns the gene PTCH1 and neoplasm.