DAPK1 and renal cell carcinoma: Combining the results of the current study with previous investigations, frequent epigenetic changes (⩾20%) in RCC include promoter methylation of RASSF1A, TIMP3, DAPK, SLIT2, MT1G and GSTP1 (Esteller et al, 2001a; Nojima et al, 2001, Dreijerink et al, 2001; Morrissey et al, 2001, Morris et al, 2003).