MUC5AC and cancer: In searching for a simple, cost effective and non-invasive screening assay that could pick up breast malignancy in its early stages it should be noted that the MUC1 mucin is expressed by other carcinomas such as ovarian and lung, and IgG autoantibodies to MUC1 carrying core3 or STn glycans have been detected in sera from patients with these cancers [13].