In comparison, we also tested the effects of the combination of HA-PEI/HA-PEG/MDR1 siRNA CD44 targeted nanoparticle and paclitaxel on tumor growth in drug sensitive SKOV-3 (not express MDR1 and Pgp) xenograft mice model that did not highly express Pgp. The gene discussed is CD44; the disease is neoplasm.