Abstract: The invention concerns a novel approach for treating cystic fibrosis using, in particular, anti-cancer chemotherapy. For the treatment of cystic fibrosis it proposes the use of at least one product which when administered to a patient brings about the expression or overexpression of an ABC carrier compound, in particular glutathione carrier. Preferably, the products used are anti-cancer products whose administration brings about the expression of MRP and/or MDR protein. The invention is also applicable to the treatment of rheumatoid polyarthritis or asthma. More specifically, the compounds are selected among cyclophosphamide, aclarubicin, doxorubicin, daunorubicin, epirubicin, idarubicin, zorubicin, pirabucin, colchicine, videsine, vinorelbine, vincristine, binblasine, azithromycin, erythromycin, ifosmamide, N-acetyl cysteine, N-acetyl lysine and/or a CFTR protein fragment comprising the NBF1 domain.