ERBB4 and ovarian cancer: Although early studies suggested that ErbB4 expression is either absent or decreased in some ovarian cancers when compared with normal ovarian tissues (Scoccia et al, 1998; Srinivasan et al, 1998), recent investigations using either IHC, RT–PCR, or western blotting techniques have demonstrated the presence of ErbB4 in a high percentage of ovarian tumours (Gilmour et al, 2001; Pejovic et al, 2009), and RT–PCR has detected at least four different ErbB4 splice variants in both established and primary ovarian cancer cell lines (Gilmour et al, 2001).