<prompt> Which anticancer drug inhibits dihydrofolate reductase?VincristineMethotrexatePaclitaxelCisplatin  <response>: Ref: K.D. Tripathi, 6th ed. pg. 823 Methotrexate is one of the oldest and highly efficacious antineoplastic drugs MOA: It inhibits dihydrofolate reductase DHFRase- blocking the conversion of dihydrofolic acid DHFA to tetrahydrofolic acid THFA which is an essential coenzyme required for one carbon transfer reactions in de novo purine synthesis and amino acid interconversions. DHFRase inhibitors are: methotrexate, Pemetrexed, Pralatrexate Vincristine is a mitotic spindle formation inhibitor Paclitaxel is a spindle breakdown inhibitor Cisplatin is a platinum based compound. 