MUC5AC and signet ring cell carcinoma: Signet-ring cell carcinoma (SRCC) is a unique subtype of mucin-producing adenocarcinoma characterized by abundant intracellular mucin accumulation, with a poor prognosis across various organs such as the stomach and colon (Wu et al. 2018; Hayashi et al. 1999; Frost et al. 1995; Kitamura et al. 1985; Randolph et al. 1997; Yamashina 1986).