To determine whether there was any relationship between SLIT2 promoter methylation and de novo methylation of RASSF1A and CASP8 promoters, we compared the frequencies of RASSF1A and CASP8 methylation in tumours with and without SLIT2 methylation (using previously published RASSF1A and CASP8 methylation data (Astuti et al, 2001). Here, CASP8 is linked to neoplasm.