PCNA and neoplasm: To confirm the role of miR-28-5p/RAP1B axis in tumor cell proliferation or metastasis in vivo, we performed the immunohistochemistry analysis to assess the proliferative activity by using anti-Ki-67 and anti-PCNA monoclonal antibody in the tumors from mice implanted with control cells, miR-28-5p-overexpressing cells and RAP1B-overexpressing cells.