A 34-year-old woman comes to the physician for a 3-month history of silvery scales on her elbows and knees. The condition has been poorly responsive to topical calcipotriene, triamcinolone, and coal tar. An oral drug that inhibits which of the following is the most appropriate next step in pharmacologic therapy?
Calcineurin
Dihydrofolate reductase
Dihydroorotate dehydrogenase
DNA replication via alkylation
IMP dehydrogenase
mTOR
Purine synthesis
Ribonucleotide reductase
