DHFR and cancer: For example, mir-24 regulates expression of anti-cancer drug methotrexate (MTX) target dihydrofolate reductase (DHFR) by binding to its 3′UTR; a SNP in DHFR 3′ UTR results in loss of the miR-24 function (miRSNP), an increase in DHFR expression and MTX-chemoresistance [4].