We calculated the log odds ratio of the enrichment of hotspot mutations in TF binding regions and conserved DNA elements. Gastric-specific TFBSs were defined as a ChIP-seq peak of a TF in any of the ENCODE cell lines that overlaps a gastric tissue DNaseI hypersensitivity site (data from Roadmap Epigenomics). Constitutive TFBSs are defined as TFBSs with Ptfbs > 0.75, where Ptfbs is the probability that the TFBS is bound by a TF for any given ENCODE cell line. Ptfbs for all TFBSs were obtained from the ENSEMBL regulatory build. Conserved elements generated by GERP73 from the alignment of hg19 to 36 mammals were downloaded from the UCSC genome browser.