In addition, expression of the proline-rich protein (PRAS40) that binds to 14-3-3 proteins and to mTOR to transduce AKT signaling to the mTOR complex was much higher in IM-resistant GIST cells when compared to parental IM-sensitive GIST T-1 cells. This evidence concerns the gene AKT1S1 and gastrointestinal stromal tumor.