The invention describes compositions and methods of use for 2,5-dihydroxybenzene sulfonic acid compounds and pharmaceutically acceptable salts thereof. The invention provides methods for (a) treating skin cancer； (b) treating cancer of the organs； (c) treating leukemia； (d) improving the efficacy of chemotherapy, radiation therapy and/or cancer immunotherapy； (e) treating rosacea； and (f) treating psoriasis by administration of a composition comprising at least one 2,5-dihydroxybenzene sulfonic acid compound or a pharmaceutically acceptable salt thereof, and, optionally at least one therapeutic agent. Also disclosed are compositions comprising administration of at least one 2,5-dihydroxybenzene sulfonic acid compound, or a pharmaceutically acceptable salt thereof, and, at least one therapeutic agent. In the invention the 2,5-dihydroxybenzene sulfonic acid compounds or pharmaceutically acceptable salts thereof are 2,5-dihydroxybenzene sulfonic acid, calcium 2,5-dihydroxybenzenesulfonate, potassium 2,5-dihydroxybenzenesulfonate, magnesium 2,5-dihydroxybenzenesulfonate and diethylamine 2,5-dihydroxybenzenesulfonate.
