Considerable efforts have been made to achieve two clinical goals: 1) turn off ABC drug pumps such P-gp (ABCB1), BCRP (ABCG2), and MRP1 (ABCC1) to prevent multidrug resistance; and 2) repair folding mutants of CFTR (ABCC7; cystic fibrosis), BCRP (ABCG2; gout), ABCB4/ABCB11 (progressive familial intrahepatic cholestasis), ABCA1 (Tangier disease), ABCC2 (Dubin-Johnson syndrome), ABCC6 (pseudoxanthoma elasticum), and ABCC8 (hyperinsulinimic hypoglycemia of infancy) using small molecules called correctors or pharmacological chaperones. This evidence concerns the gene ABCC1 and pseudoxanthoma elasticum (inherited or acquired).