Circulating tumor cells (CTCs) derived from local tumors are capable of escaping immunosurveillance and targeting homotypic tumors due to cell surface interactions including Thomsen–Friedenreich antigen and E-cadherin, and inspired by this self-adherence property, researchers have developed the biomimetic cancer cell membrane-coating technique for active tumor-targeted drug delivery [13,68]. The gene discussed is CDH1; the disease is cancer.