ARID1A and cancer: The two most frequently mutated epigenetic modifier genes, ARID1A and KMT2D, with overall mutation prevalence of 25.2% and 16.7%, respectively, in TCGA, were mutated in 24.8% and 16% of higher CDX2-expressing cancers and in 30.6% and 21% of CDX2-lower-expressing cancers (Fisher’s exact test p = 0.41 and 0.34, respectively, Table 4).