RT-qPCR was used to detect the relative mRNA level of 3 NRGs in 31 pairs of GC and adjacent normal tissues, Results from RT-qPCR revealed that the expression levels of AXL, RAI14, and NOX4 were higher in GC tissues than in nearby normal tissues next to cancer (Figure 4C), further demonstrating from the perspective of basic experiments that the reliability of NRGPS for determining GC prognosis. This evidence concerns the gene NOX4 and gastric cancer.