According to the RNA interference theory, endonuclease cleaves the dsRNA fragments produced during cell transcription into several small fragments of shRNA, and binds to the ribozyme complexes to silence the targeted mRNA homologous to shRNA (i.e. the epidermal growth factor receptor is overexpressed in ovarian cancer), thereby inhibiting the expression of ovarian cancer protein and causing tumor cell death22,23. The gene discussed is EGFR; the disease is ovarian carcinoma.