Gastric cancer (GC) can be classified histologically into various types.[1] Although the incidence of GC has decreased, the incidence of signet ring cell (SRC) carcinoma remained high.[2] SRC is a distinct histological type with cells containing abundant intracytoplasmic mucin,[3] and its characteristic ring appearance is due to its mucin-rich cytoplasm and crescent-shaped nucleus. The gene discussed is MUC5AC; the disease is gastric cancer.