Previous genomic and mechanistic studies showed that CXCL12, CXCR4, and MMP9 were critical pro-invasion genes repressed by the AhR [29] in GBM cells and both OME and ESO decreased expression of all three genes in wild-type 15-037 cells (Figure 2E). This evidence concerns the gene CXCR4 and otitis media with effusion.