ERBB2 and metastatic colorectal cancer: In “HER2 Amplification for Colo-rectaL cancer Enhanced Stratification” HERACLES A (trastuzumab plus lapatinib), HERACLES B (pertuzumab plus trastuzumab-emtansine), Mountaineer (trastuzumab plus tucatinib), and “Multicenter Phase II study to evaluate efficacy and safety of combination therapy with trastuzumab and pertuzumab in patients with HER2-positive metastatic colorectal cancer” TRIUMPH (trastuzumab and pertuzumab) phase II trials, the HER2 blockade was effective and had a manageable safety profile in HER2-positive (HER2+) pretreated mCRC patients (Table 2) [30,31,32,33].