Aiming at the high expression of epidermal growth factor receptor (EGFR) in ovarian cancer, the investigators linked the dextran modified SPIO with polylysine PLL to form the SPIO-PLL complex, and successfully constructed the SPIO-shRNA molecular probe for short hairpin RNA (shRNA) in epidermal growth factor receptor (EGFR)21. This evidence concerns the gene EGFR and ovarian carcinoma.