The present study did not examine the effect of ERβ expression on GBM cells; however, according to the literature, ERβ agonists induce a decrease in proliferation of glioma cell lines (T98G, U87, LN229, U138, M059J, M059K) [43,56] and inhibit the cell cycle in the G2/M phase [43]. This evidence concerns the gene ESR2 and glioma.