In terms of the relationship between RAB21 expression in tissues and cancer, Lin et al (29) and Anand et al (30) demonstrated that high RAB21 expression was significantly correlated with poor overall survival in breast invasive carcinoma (BRCA) and pancreatic ductal adenocarcinoma (PDAC), using Gene Expression Profiling Interactive Analysis and The Cancer Genome Atlas databases, respectively (29,30). This evidence concerns the gene RAB21 and pancreatic ductal adenocarcinoma.