The important role of endothelial cells in homing mechanisms is mostly transduced by specific integrins or cell adhesion molecules (E-selectin ligand, β1 integrin, Rac1, CX3CL1/CX3CR1, ANXA2/ANXA2R) and is therefore crucial, as endothelial cells are the first cells in contact with cancer cells arriving in the bone marrow [18]. The gene discussed is CX3CL1; the disease is cancer.