In order to elucidate the possible mechanism(s) of resistance to anti-HER2 treatments, in this study we have used LIM1215 and SW48 human colon cancer cell lines and their HER2-amplified derivatives (LIM1215-HER2 and SW48-HER2) to perform in vitro and in vivo studies using different xenograft models in order to identify novel therapeutic options [17, 23, 26]. Here, ERBB2 is linked to malignant colon neoplasm.