ERBB2 and neoplasm: The preclinical study found that treatment with HL might result in an enhanced anti‐tumor activity probably due to more complete blockage of HER2 signaling and synergistic drug interactions, for instance, lapatinib enhanced immune‐mediated trastuzumab‐dependent cytotoxicity, which could accumulate HER2 at the cell surface.5, 6 Despite the fact that no direct clinical evidence of HLC was reported, the combination of HL was explored in several trials.