DIRAS1 and colorectal cancer: Downregulation of DIRAS-1 expression was reported to be partly due to aberrant promoter methylation in esophageal squamous cell carcinoma, renal cell carcinoma, and colorectal cancer [4,5,7] and increased DIRAS-1 expression was shown in one renal cell carcinoma cell line after treatment with a histone deacetylase inhibitor [8].