SELP and neoplasm: L-selectin-deficient (L−/−) mice showed a significant reduction in metastasis highlighting the role of L-selectin in facilitating metastasis; therefore, heparin administered at early time point before tumour inoculation acts by inhibiting P selectin (platelets-tumour interaction) while when administered in a later time after tumour inoculation, heparin acts on L selectin on leukocyte, NK, monocyte (39, 177).