Internalization of anti-SSTR2A MAbs by D341 MED cells. Standard internalization assays were performed following binding of anti-SSTR2A MAbs to cells at 4°C, washing, and incubation at 37°C for various intervals. (A–C, E) Percent input label bound over time in each of the examined compartments: cell membrane associated, cell associated, and released (supernatant). (D, F) Proportion of label released to the extracellular milieu that is MAb bound or free.