ERBB2 and neoplasm: Currently, there are eight clinically approved therapeutic mAbs targeting five tumor-associated proteins, including CD20 (rituximab, Ibritumomab tiuxetan, and tositumomab), CD33 (gemtuzumab), CD52 (alemtuzumab), HER2/neu (trastuzumab), and EGFR (cetuximab, panitumumab).