ICAM1 and breast cancer: In addition, the under-glycosylated form of MUC1 expressed on breast cancer cells binds to E-selectin, whereby it interacts with intercellular adhesion molecule-1 (ICAM-1), a member of immunoglobulin superfamily (IgSF) expressed on endothelial cells, to facilitate rolling and firm adhesion of breast cancer cells to the BE [33,34].