To further address whether IGFBP5 promotes GSC invasion and tumor progression in vivo, we knocked down the expression of IGFBP5 in a patient-derived GSC (PDC) and tested the resulting antitumor activity in PDC-derived orthotopic xenograft models (PDXs), which generally recapitulate both the genetic and histological profiles of donor patient-derived tumors. The gene discussed is IGFBP5; the disease is neoplasm.