EGFR and familial pancreatic carcinoma: We demonstrate that the number of C225 antibodies on a GNP (C225∶GNP ratio), the hydrodynamic size, the available reactive surface area and the ability of the nanoconjugate to sequester EGFR, all play critical roles in effectively targeting tumor cells in vitro and in vivo in an orthotopic model of pancreatic cancer.