ERBB4 and prostate neoplasm: The data presented in Section 3.2 predict EGFR/ERBB4, MET and IGF-1R signaling as relevant regulators of LSCmed cell proliferation, and suggest that the enrichment of their ligands in the microenvironment of Pten-null mouse prostates might contribute to the amplification of the LSCmed cell compartment observed in prostate tumors of these mice [5].