GSTP1 and cancer: Canfosfamide is a conjugate of a glutathione (GSH) analog and an N,N,N',N'-tetrakis(2-chloroethyl) phosphorodiamidate that was designed to be metabolically activated by glutathione-S-transferase P1-1 (GST P1-1), an enzyme that is over-expressed in many human cancers including ovarian cancer.