In our Wilms' tumour series, the frequency of SLIT2 promoter methylation in Wilms' tumours was similar to that for CASP8 but higher than that for TSGs, which may show frequent promoter methylation in other tumour types, for example, MGMT (30%), NORE1A (15%), p14ARF (15%), p16INK4a (10%), DAPK (11%), CRBP1 (9%), RARB2 (0%), CDH13 (0%) and CDH1 (3%) (Morris et al, 2003). The gene discussed is RBP1; the disease is Wilms tumor.