Provided herein are Aminopurine Compounds having the following structures: wherein R1, R2, and R3 are as defined herein, compositions comprising an effective amount of an Aminopurine Compound, and methods for treating or preventing a cancer, for example, melanoma.本文提供具有以下結構的胺基嘌呤化合物:其中R1、R2及R3如本文所定義,包含有效量之胺基嘌呤化合物的組合物,及用於治療或預防癌症(例如黑素瘤)的方法。