HGF and renal cell carcinoma: HGF, the MET ligand, was detected by ELISA in the plasma and tumors of immunodeficient NOD-SCID γ (NSG) mice implanted subcutaneously with RCC PDX, confirming autocrine production of HGF in this model (Supplemental Table 1; supplemental materials are available at http://jnm.snmjournals.org).