SIRT1 and carcinoma of esophagus: HIC1 is an epigenetically regulated sequence‐specific transcriptional repressor in many cancers including prostate, pancreatic and oesophageal cancers.31, 32, 33 Inactivation of HIC1 expression is known to up‐regulate SIRT1 expression and allow cells to bypass apoptotic cell death.34, 35 HIC1 is also known to play a critical role in DNA damage response.36, 37 HIC1 forms a transcriptional repression complex with SIRT1 through an N‐terminal POZ (Pox virus and zinc finger) domain.