Cyclo(-RGDfK) 是有效，選擇性的整合素 αvβ3 抑制劑，其 IC50 值為 0.94 nM。Cyclo(-RGDfK) TFA 通過與細胞表面的 αvβ3 整合素結(jié)合，特異性靶向腫瘤微血管和癌細胞。

Cyclo(-RGDfK) is a potent and selective inhibitor of the αvβ3 integrin, with a IC50 of 0.94 nM[1]. [66Ga]DOTA-E-[c(RGDfK)]2 can be prepared with high radiochemical purity (>97%), specific activity (36-67GBq/μM), in vitro stability, and moderate protein binding. MicroPET imaging up to 24 post-injection showed contrasting tumors reflecting αvβ3-targeted tracer accumulation[2].