MUC5AC and colon mucinous adenocarcinoma: This is perhaps a slightly surprising result, as mucinous adenocarcinoma of the colon or rectum is well recognised to have a poorer survival rate when compared to non-mucinous adenocarcinoma [37] and hence there must be other influences, yet to be identified, that are specific to mucin-producing tumours that are responsible for the higher expression levels of PEDF.