ERBB2 and cancer: In view of this, based on MWCNTs and anionic porphyrin, herein we design a simple and sensitive impedance sensor for the determination of DNA fragment specific to the human epidermal growth factor receptor-2 (HER2), which is a tumor marker for the diagnosis of many cancers such as lung cancer, gastric cancer, breast cancer, prostate cancer and ovarian cancer [32,33].