Alterations in NF1 gene expression in TCC were first reported in 1999 [148], where decreased NF1 gene expression was observed in 83% (23/29) of TCC specimens (as estimated by immunohistochemistry), whilst NF1 mRNA levels were markedly lower in TCC tissue as compared with those in adjacent non-neoplastic urothelium. Here, NF1 is linked to tarsal-carpal coalition syndrome.