MUC4 and cancer: The kinetic trap model,[3] which underlies the prevailing understanding that increased expression of glycocalyx molecules monolithically promotes cancer growth, survival and metastasis,[2, 47] represents only one of the three possible states, a state that is achieved when the glycocalyx is dominated by larger (>1000 amino acid) mucins such as MUC1,[48] MUC4,[8] and MUC16,[48] or by a relatively uniform distribution of smaller mucins.