Methylation of RASSF1A was first reported in lung and breast cancers, but subsequently we and others demonstrated RASSF1A methylation in renal cell carcinoma (RCC) and in common childhood tumours such as neuroblastoma (NB) and Wilms' tumour (Astuti et al, 2001; Dreijerink et al, 2001; Lo et al, 2001; Morrissey et al, 2001; Wagner et al, 2002). Here, RASSF1 is linked to breast cancer.