Proto-oncogene tyrosine-protein kinase MER is an enzyme that in humans is encoded by the MERTK gene. This gene is a member of the MER/AXL/TYRO3 receptor kinase family. MerTK is the mammalian ortholog of the chicken retroviral oncogene product v-Eyk. This protein plays a critical role in macrophage activation, platelet aggregation, clot stability and the efficient removal of apoptotic cells. Mutations in this gene have been associated with disruption of the retinal pigment epithelium (RPE) phagocytosis pathway and onset of autosomal recessive retinitis pigmentosa.
