This is the first study that attempt to evaluate the in vivo efficacy and feasibility of dual blockade of FASN and the HER2 signaling pathway in HER2-positive patient tumor samples (HER2-PDX) and in HER2 samples of a patient who relapsed after trastuzumab and lapatinib therapies (HER2-PDXR). This evidence concerns the gene FASN and neoplasm.