Fig. 3
A simplified diagram of the therapeutic breast cancer network. The main targetable hubs are ER and HER2 receptor. The PI3K/Akt/mTOR hub was relatively recently identified to be the common mechanism of targeted therapy resistance. Circles and rectangles represent cellular receptors and signaling pathways, respectively. The pentagons represent other unspecified molecules interacted with the hubs. Arrows represent the directions of signals. (E estrogen, ER estrogen receptor, PR progesterone receptor, HER2 HER2 receptor, RTKs receptor tyrosine kinases)