The results of AlphaLISA showed that the levels of TPI1-Abs, HOOK2-Abs, PUF60-Abs, PRDX4-Abs, HS3ST1-Abs, TACSTD2-Abs, TUBA1B-Abs, AKR1C3-Abs, BAMBI-Abs, DCAF15-Abs, PDE4DIP-Abs, ECSA1-Abs, ECSA2-Abs, and CNNL2-Abs were significantly higher in patients with ESCC, GC, or CC than in HD (Figures 2A–2F and Supplementary Figures 2A–2H). Here, PDE4DIP is linked to gastric cancer.