NRG3 and neoplasm: Our results in two bladder cancer cell lines RT4 and T24, which have been used as models of superficial noninvasive and invasive tumours, respectively (Theodorescu et al, 1990; 1998; Redwood et al, 1992; Booth et al, 1997; Davies et al, 1999), show a similar pattern of mRNA expression as in bladder cancer biopsies, except for HRG3.