Our subsequent studies demonstrated that these miRNAs have direct functional significance in colorectal cancer by regulating key targets such as thymidylate synthase (TYMS, TS) [20], dihydrofolate reductase (DHFR) [7], histone deacetylase [3], E2F3, and Bcl-2 [18]. This evidence concerns the gene DHFR and colorectal cancer.