ABCB1 and laryngotracheoesophageal cleft: ABCB1 is ubiquitously present among LC, ovarian cancer, breast cancer, glioblastoma and renal cancer, and it is responsible for promoting tumour chemoresistance to drugs, such as, anthracycline actinomycin D, cisplatin, colchicine, etoposide, teniposide, methotrexate and others.