ABCC5, also named as MOAT-C, pABC11, SMRP and MRP5, belongs to the ABC transporter superfamily, ABCC family and Conjugate transporter (TC 3.A.1.208) subfamily. ABCC5 acts as a multispecific organic anion pump which can transport nucleotide analogs. ABCC5 functions in the cellular export of its substrate, cyclic nucleotides. This export contributes to the degradation of phosphodiesterases and possibly an elimination pathway for cyclic nucleotides. Studies show that ABCC5 provides resistance to thiopurine anticancer drugs, 6-mercatopurine and thioguanine, and the anti-HIV drug 9-(2-phosphonylmethoxyethyl) adenine. ABCC5 may be involved in resistance to thiopurines in acute lymphoblastic leukemia and antiretroviral nucleoside analogs in HIV-infected patients. Alternative splicing of this gene has been detected; however, the complete sequence and translation initiation site is unclear.