Toll-like receptor 9 (TLR9) expression by PCa cells, which appears central to tumorigenesis, stimulates recruitment of PMN-MDSCs via the proteins S100A8 and S100A9, and upregulates the transcription factor STAT3 which in turn inhibits CD8 T cell anti-tumor activity (83). The gene discussed is TLR9; the disease is posterior cortical atrophy.