It was observed that for the case of mice implanted with targeted drug-loaded microspheres (PLGA-PEG_PGS-LHRH and PLGA-PEG_PTX-LHRH), there was no recurrence of tumor after drug released from the microspheres for 18 weeks (See representative result in Fig. 10If). Here, GNRH1 is linked to neoplasm.