DHFR (Dihydrofolate Reductase): DHFR, or dihydrofolate reductase, is a critical enzyme involved in the metabolic pathways that synthesize and repair DNA. It catalyzes the reduction of dihydrofolate to tetrahydrofolate, a cofactor for the synthesis of purines, thymidylate, and several amino acids. This process is essential for cell division and growth. Inhibitors of DHFR, such as methotrexate, are widely used in chemotherapy, as they target rapidly dividing cancer cells by blocking DNA synthesis, highlighting DHFR's crucial role in cellular proliferation and cancer treatment....