In some embodiments, the present invention provides methods of treating a tumor in a subject. In some embodiments, the methods may include a step of administering to the subject a therapeutic composition that comprises: (a) mycophenolic acid, an analogue thereof, or a derivative thereof and (b) at least one anti-neoplastic agent. In some embodiments, the antineoplastic agent may include at least one of 5-fluouracil (5-FU), paclitaxel, oxaliplatin, doxorubicin, etoposide, irinotecan, bleomycin, imiquimod, 13-cis-retinoic acid, and combinations thereof. In some embodiments, the relative concentrations of the mycophenolic acid, the analogue thereof, or the derivative thereof, and the at least one anti-neoplastic agent correspond to their respective IC50 values. In some embodiments, the methods of the present invention may be used to treat tumors associated with at least one of an oral cancer, a skin cancer, a breast cancer, a prostate cancer, precancerous lesions thereof, hyperplastic lesions thereof, and benign tumors thereof.
