By treating mice with positively charged polyethylenimine (PEI)‐condensed DNA oligo‐based O'PROTAC, we demonstrated that LEF1 OP‐V1 effectively inhibited PC‐3 and DU145 tumor growth in mice compared to the treatment of phosphate‐buffered saline (PBS) or control OP (Figure 4C–F). The gene discussed is LEF1; the disease is neoplasm.