GRPR and lip and oral cavity carcinoma: In this study, we used a GRPR-specific Alexa Fluor 750 (AF750) labeled BBN antagonist, AF750-6Ahx-Sta-BBN, to evaluate the expression of GRPR in OSCC and normal epithelial tissues by immunofluorescence, and the binding selectivity and affinity to human oral cancer cell line HSC-3 cells in vitro.