RARB and neoplasm: Numerous tumor-related genes, including FHIT[6], RARβ[6]–[8], CDKN2A[7], [9], [10], MGMT[7], [9], [11], RASSF1[6], RBP1[7], [8], CDKN2AB[10], MT1G[7], MLH1[10], [12], CDH1[13], VHL[6], MT3[14], C2orf40[15], RPRM[16], CLND3[7], APC[17], and UCHL1[18], which are involved in various carcinogenic pathways, have been revealed to be frequently hypermethylated in ESCC.