PIK3CA and breast cancer: In this regard, ongoing clinical trials are recruiting patients for testing new drugs targeting alternative biomarkers (e.g., the effectors of Ras-dependent pathways [15], poly-ADP ribose polymerase (PARP) [16], neurotrophic receptor tyrosine kinase 1,2,3 (NTRK1/2/3), c-ros oncogene 1 (ROS1), anaplastic lymphoma kinase (ALK) [17], and the signalling effectors of the PI3K [18], used as monotherapies or combinatorial approaches for the management of BC and TNBC patients.