The tracer was then used for autoradiography studies and to screen nine human BC cell lines in vitro (SUM44PE, MCF7, T47D, UACC812, BT474, CAMA-1, SUM52PE, HCC1806, Hs578t) with regard to their GRPR expression by cell uptake/internalization studies. The gene discussed is GRPR; the disease is breast cancer.