FOSL1 and central nervous system cancer: Next, FOSL1 expression levels were elevated by introducing FOSL1 tagged with Myc-DDK/FLAG (FOSL1-FLAG) into glioma cells, we confirmed high transfection efficiency by observing the robust expression of FOSL1 and FLAG protein in A172, U87MG, and PDX-L14 cells (Fig. 7A).