To examine the effect of inhibiting the AKT-PI3K pathway on breast cancer invasion in this 3D context, mutant PtenG129E/+ cells were allowed to invade and were treated with either the pan-PI3K inhibitor BKM120, which acts upstream of AKT, or the downstream inhibitor rapamycin, targeting mTORC1 (fig. Here, PIK3CA is linked to breast cancer.