In this study, it was found that the gene and protein expression levels of ACAT1 were down-regulated in CRC as compared to BCT, which was in agreement with a study conducted in early1990s that ACAT activities increased in differentiated HT29 cell types, but was hardly detectable in undifferentiated cell types [20], suggesting that aggressive phenotype CRC cells related to down-regulation of ACAT. This evidence concerns the gene ACAT1 and colorectal carcinoma.