PROM1 and neoplasm: Recently, some chimeric measles viruses were recombined with antigens for tumor-specific ligands such as CD20, CD133, and synthetic microRNA for tumor-targeting sequences [46, 47], however, these chimeric viruses with retargeted tropisms also raised safety concerns, including the ability of these chimeric virus mutations to impair cell entry [48] and their limited specificity for certain tumor types.