PIK3CA and breast cancer: For example, the use of network approach has been suggested as useful: (i) for cancer intervention through the targeting of key phosphotyrosine sites and their associated signaling hubs in the network27; (ii) to predict breast cancer subtype-specific drug targets28; (iii) to suggest tumor clinical phenotypes using genome sequencing data29; and (iv) to identify that the feed-forward loop - FFL (PDGF/FLT1/SHC1) is significantly enriched in the PIK3CA-mutated luminal-A tumor patients and predicts survival outcome30.