The drug-resistant cell lines displayed decreased sensitivity to YM155, with upregulation of the ATP-binding cassette (ABC) transporter ATP Binding Cassette Subfamily B Member 1 (ABCB1, also known as P-glycoprotein or multidrug resistance gene 1, MDR1; causes cellular YM155 efflux) and downregulation of Solute Carrier Family 35 Member F2 (SLC35F2, mediates cellular YM155 uptake) as the major drug-specific resistance mechanisms and loss of p53 function as resistance mechanism that affects all approaches targeting survivin in neuroblastoma. The gene discussed is SLC35F2; the disease is neuroblastoma.