Cell-cell and cell-stroma interactions using various adhesion molecules including very late antigen-4 (VLA-4), vascular adhesion molecule (VCAM), leukocyte function-associated antigen 1 (LFA-1), and intercellular adhesion molecule-1 (ICAM-1) [34] are important throughout myeloma pathogenesis and also contribute to drug resistance although multiple myeloma patients are initially responsive to these drugs. Here, ICAM1 is linked to plasma cell myeloma.