CTCF and cat-eye syndrome: In addition, we observed a number of CES‐R/M‐specific mutations in epigenetic regulators such as ARID1A, ARID1B, CTCF, KMT2C, KMT2D, PBRM1, and SETBP1, suggesting that metastatic progression of CES may be associated with loss of epigenetic regulation.