PTK6 was shown to be overexpressed in two-thirds of breast carcinomas (Mitchell et al, 1994; Barker et al, 1997; Llor et al, 1999; Born et al, 2005; Aubele et al, 2007; Ostrander et al, 2007), and expression is elevated in colon tumours and several cancer cell lines (Barker et al, 1997; Llor et al, 1999; Kamalati et al, 2000; Meric et al, 2002; Derry et al, 2003). Here, PTK6 is linked to breast carcinoma.