Axl siRNA knock down and Axl inhibitors (R428 and foretinib) significantly reduced RGC cell viability determined by WST-1 (Figure 2B; Supplementary Figure S4) and colony formation assays (Figure 2C), suggesting that Axl signaling promotes the viability of PLX4720 resistant glioma cells. The gene discussed is AXL; the disease is glioma.