In addition, we found that loss of SLC26A9 expression was associated with tumor stage, lymph node stage, metastasis stage and TNM stage of GC, but not with age or gender in the diffuse type group, which consisted of pure signet ring carcinomas and poorly differentiated adenocarcinomas with signet ring carcinoma. The gene discussed is SLC26A9; the disease is signet ring cell carcinoma.