The transmembrane glycoprotein, Mucin1 (MUC1), is a mucin family member protein that is expressed on normal glandular epithelial cells and ductal epithelial cells and abundantly expressed on cancer cell surfaces; it is associated with cancer progression and is referred to as tumor associated MUC1 (TA-MUC1) (Nath and Mukherjee, 2014). The gene discussed is MUC5AC; the disease is cancer.