ERBB3 and neoplasm: GSK2849330 was labeled with Zirconium-89 (89Zr) or with a fluorescent probe (VivoTag 680) for in-vivo Immuno-PET, and in-vivo/ex-vivo optical imaging was used to investigate the biodistribution of GSK2849330 and to determine the relationship between dose and receptor-occupancy in HER3 negative and positive expressing human tumor-bearing mice.