New sulfonamide derivatives, prepared by optimized synthetic procedures, were evaluated by QSAR analysis to estimate their inhibition constants (KIs) against to four hCA isoforms (hCA I, II, IV, and hCA IX) and inhibition selectivity expressed as KI ratio of the cytosolic hCA II and tumor-associated, membrane-bound hCA IX isoforms (hCA II/hCA IX). The gene discussed is CYP24A1; the disease is neoplasm.