CFTR and cystic fibrosis: In line with the lab strains, most clinical isolates (CF MUC 5, CF MUC 148, CF MUC 181, CF MUC 264, CF MDR 672, CF MDR 674, CF MDR 2539, CF MDR 2540, and CF MDR 2588) exhibited increased tolerance to kanamycin in MM9 compared to GM9 (Fig. 2C and Table 3).