TCGA analysis showed that SOX9 was upregulated in STAD patients compared with that in normal patients (p < 0.001), and the OS of STAD patients with a high expression of SOX9 is poorer than that in patients with low expression of SOX9, but the statistical difference is not obvious (p = 0.31).<h4>Conclusion</h4>SOX9 expression was associated with the depth of tumor invasion, TNM stage, and poor OS of GC patients. Here, SOX9 is linked to gastric adenocarcinoma.