Indoline derivative compounds that act as EWS-FLI1 transcription factor inhibitors are provided. Also provided are pharmaceutical compositions of the indoline derivatives, methods of synthesizing the same, methods of treating using same, and assays for identifying the inhibitors of EWS-FLI1 oncoprotein.本發明提供用作EWS-FLI1轉錄因子抑制劑之二氫吲哚衍生物化合物。亦提供該等二氫吲哚衍生物之醫藥組合物、合成該等衍生物之方法、使用該等衍生物之治療方法,及用於鑑別EWS-FLI1致癌蛋白抑制劑之分析。