Rab27b promotes malignant cell phenotypes and is associated with poor patient prognosis in several cancers.5–7,29,30 Our study shows that Rab27b expression was increased after irradiation and was sustained for 7 days, supporting the findings that Rab27b expression is increased at several endpoints of assays and experiments, such as the cell counting assay, colony formation assay, paracrine assay, and in vivo experiments. Here, RAB27B is linked to cancer.