GPR18 and neoplasm: The results of protein expression analysis of the 15 genes showed that CX3CR1, GIP, GNGT1, GPR18, NTS, and LEP were negative in tumor tissue and normal tissue, the expression of CNR2 was significantly lower in tumor tissue, H3F3C and HIST1H2BC were not significantly different between tumor tissue and normal tissue, and CXCR5, HIST2H3C, and GPSM2 were more highly expressed in tumor tissue than in normal tissue.