Importantly, the GC proteomics database (GCPDB) [28] has previously reported differential levels of IGFALS, LBP, S100A12, F13A1, SAA1/SAA2, PRCP, and IGHG1 in plasma/serum proteome MS analysis of GC patients at various stages, further validating the relevance of our findings. Here, IGHG1 is linked to gastric cancer.