H-Glu[cyclo(-Arg-Gly-Asp-D-Phe-Lys)]-cyclo(-Arg-Gly-Asp-D-Phe-Lys)

E(c(RGDfK))₂ (SU 016), a dimeric form of c(RGDfK), showed improved tumor targeting properties compared to the monomer. E(c(RGDfK))₂ can be easily conjugated to dyes, drug molecules, or chelators. The ⁶⁸Ga complex of DOTA-E(c(RGDfK))₂ has been evaluated as theranostic radiopharmaceutical