HDAC1 and carcinoma of esophagus: The higher expression of PER‐2/per‐2 in metastatic oesophageal carcinoma cells inhibits the expression of E‐cadherin, while HDAC‐1 is involved in the inhibition of E‐cadherin induced by PER‐2 and blocks the ability of HDAC‐1 to inhibit the migration of oesophageal cancer cells.32