Axl is a receptor tyrosine kinase that contains both immunoglobulin and fibronectin III
repeats in its extracellular domain reminiscent of cell adhesion molecules. Expression of the
receptor tyrosine kinase Axl in the 32D myeloid cell line permits aggregation of cells in
response to treatment with the native ligand GAS6; this aggregation was not observed in
untreated 32D-Axl cells nor in treated parental cells. This aggregation can be blocked by the
addition of excess Axl extracellular domain peptide and does not require intracellular Axl …