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. The gene discussed is ARID1B; the disease is cat-eye syndrome.