SLC29A1

The monoclonal antibodies that recognize hENTl are useful as companion diagnostics for established cancer drugs such as nucleoside analogue drugs and/or drugs derived from nucleoside analogues. For example, the hENTl antibodies are useful in conjunction with chemotherapy agents such as pyrimidine derivatives including, for example, cytarabine, gemcitabine, azacytidine, and derivatives thereof, and purine derivatives including, for example, fludarabine, cladribine, clofarabine and derivatives thereof.