Their top four differentially methylated genes – comparing methylation between tumour and normal mucosa – were EYA4, HS3ST2, TFPI2 and SLIT2. Using unsupervized hierarchical clustering analysis, they found that differential methylation segregated into CIMP-H, -M and –L; however, their findings have not been independently reproduced and their study may have experienced bias due to small sample size. Here, SLIT2 is linked to neoplasm.