 Nucleoside transporters are required for nucleotide synthesis in cells that lack "de novo" nucleoside synthesis pathways, and are also necessary for the uptake of cytotoxic nucleosides used for cancer and viral chemotherapies.The gene encoding this protein is located on the short arm of chromosome 6 at 6p21.2-p21.1 on the Watson (plus) strand.It is 14,647 bases in length.