SELP and cancer: Hematopoietic and non-hematopoietic cells constitutively express CD24; Cancer stem cells overexpress CD24; Ligands: NKG2D on NK and CD8+ T cells, SIGLECs are expressed on T, B, Macs, Monocytes and DC; P-selectin is expressed by activated platelets and endothelial cells; Integrin β-1 is expressed by cancer cells