The primary cancers were identified only in 16 of these 19 patients and were gastric carcinoma, prostate carcinoma, carcinoma of unknown primary, anal squamous cell carcinoma, and colon carcinoma, and multiple endocrine neoplasia type I. It is important to note that 9 out of 19 previously reported patients received chemotherapy and five achieved remission, with most of these malignancies being mucin-rich adenocarcinomas [18–35]. Here, MUC5AC is linked to adenocarcinoma.