Mature EREG is released to the extracellular region and binds to EGFRs, leading to their activation.21,23 The expression pattern of EREG was closely correlated with Rab27b, but not Rab27a, in the 5 tested glioma cell lines, and EREG was substantially upregulated in U87MG cells. The gene discussed is RAB27B; the disease is central nervous system cancer.