MUC5AC and cancer: Some mucins, such as Mucin 2 and Mucin 16, are immunomodulatory factors that can increase the expression of chemoattractants or pro-inflammatory factors including MCP-1, IL8, and PGE2 [50,54,55] in mucin-secreting cancer cells; therefore, more monocytes/macrophages can be recruited into the local tissue.