We first examined the expression level of PPFIA1 mRNA in various tumors with the GEPIA website, and the results showed significantly higher PPFIA1 mRNA expression in several types of tumor tissues, including esophageal cancer (ESCA), pancreatic adenocarcinoma (PAAD), and thymoma tissues, compared with adjacent normal tissues (Fig. 1A). This evidence concerns the gene PPFIA1 and esophageal cancer.