Receptor, EphA2: An Eph family receptor found abundantly in tissues of epithelial origin. It is expressed in a diverse array of tissues during embryonic development, suggesting that it may play a role in embryogenesis. In adult tissues high levels of the receptor are expressed in the LUNG; SKIN; SMALL INTESTINE and OVARY.Receptor, EphA4: An eph family receptor found in variety of tissues including BRAIN. During embryogenesis, EphA4 receptor exhibits a diverse spatial and temporal patterns of expression suggesting its role in multiple developmental processes.Receptor, EphA7: An eph family receptor found widely expressed in embryo tissues, including the NERVOUS SYSTEM. In the BRAIN high levels of EphA7 expression occurs in the anterior tectum, medulla, RHOMBENCEPHALON, and SUBCOMMISSURAL ORGAN. Several isoforms of the protein occur due to multiple alternative spicing of the EphA7 mRNA.Receptor, EphA5: An eph family receptor found primarily in differentiated neuronal tissues. Several isoforms of EphA5 receptor occur due to multiple alternative RNA splicing. The protein is prominently expressed in the NEURONS of the LIMBIC SYSTEM during development and throughout adult life, suggesting its role in the plasticity of limbic structure and function.Receptor, EphA1: The founding member of the EPH FAMILY RECEPTORS. It was first cloned from an erythropoietin-producing human hepatocellular carcinoma cell line and is highly conserved among many mammalian species. Overproduction of the EphA1 receptor is associated with tumors and tumor cells of epithelial origin. It is also expressed at high levels in LIVER; LUNG; and KIDNEY; which is in contrast to many other members of the Eph receptor that are found primarily in tissues of the nervous system.Ephrin-A1: An ephrin that was originally identified as the product of an early response gene induced by TUMOR NECROSIS FACTORS. It is linked to the CELL MEMBRANE via a GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR and binds EPHA2 RECEPTOR with high affinity. During embryogenesis high levels of ephrin-A1 are expressed in LUNG; KIDNEY; SALIVARY GLANDS; and INTESTINE.Ephrin-A2: A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR-containing ephrin with a high affinity for the EPHA3 RECEPTOR. Early in embryogenesis it is expressed at high levels in the MESENCEPHALON; SOMITES; branchial arches, and LIMB BUDS.Ephrin-A5: A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR containing ephrin found in developing tectum. It has been shown to mediate the bundling of cortical axons and repel the axonal growth of retinal ganglia axons. It is found in a variety of adult tissues of BRAIN; HEART; and KIDNEY.Receptors, Eph Family: A large family of receptor protein-tyrosine kinases that are structurally-related. The name of this family of proteins derives from original protein Eph (now called the EPHA1 RECEPTOR), which was named after the cell line it was first discovered in: Erythropoietin-Producing human Hepatocellular carcinoma cell line. Members of this family have been implicated in regulation of cell-cell interactions involved in nervous system patterning and development.Ephrin-A4: A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR containing ephrin found in variety of adult tissue such as KIDNEY; LUNG; COLON and OVARY. During embryonic development, ephrin-A4 is expressed in the HIPPOCAMPUS and CEREBRAL CORTEX. It binds preferentially to ephA receptors (EPH FAMILY RECEPTORS) with the exception of the EPHA1 RECEPTOR.Ephrins: Signaling proteins that are ligands for the EPH FAMILY RECEPTORS. They are membrane-bound proteins that are attached to the CELL MEMBRANE either through a GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR or through a transmembrane domain. Many of the ephrins are considered important intercellular signaling molecules that control morphogenic changes during embryogenesis.Ephrin-A3: A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR containing ephrin with a high affinity for the EPHA3 RECEPTOR; EPHA5 RECEPTOR; EPHA6 RECEPTOR; EPHA7 RECEPTOR; and EPHA8 RECEPTOR. It is found primarily in NERVE TISSUE.Ephrin-B3: A transmembrane domain containing ephrin. Although originally found to be specific for the EPHB3 RECEPTOR it has since been shown to bind a variety of EPH FAMILY RECEPTORS. During embryogenesis ephrin-B3 is expressed at high levels in the ventral neural tube. In adult tissues, it is found primarily in the BRAIN and HEART.Receptor, EphA6: An eph family receptor that is found in a variety of neuronal regions of the BRAIN. In contrast to the other proteins in this class, it is expressed at higher levels in adult tissues than in embryonic tissues.Chimerin 1: A GTPase activating protein that is specific for RAC GTP-BINDING PROTEINS. It is expressed primarily in the brain and may be involved in signal transduction. The alternatively spliced form of CHIMERIN 1 (alpha-2 Chimerin) contains an additional src homology domain and is expressed in both the brain and testes.Ephrin-B2: A transmembrane domain containing ephrin that binds with high affinity to EPHB1 RECEPTOR; EPHB3 RECEPTOR; and EPHB4 RECEPTOR. Expression of ephrin-B2 occurs in a variety of adult tissues. During embryogenesis, high levels of ephrin-B2 is seen in the PROSENCEPHALON; RHOMBENCEPHALON; developing SOMITES; LIMB BUD; and bronchial arches.Receptor Protein-Tyrosine Kinases: A class of cellular receptors that have an intrinsic PROTEIN-TYROSINE KINASE activity.Ephrin-B1: A transmembrane domain containing ephrin that is specific for EPHB1 RECEPTOR; EPHB2 RECEPTOR and EPHB3 RECEPTOR. It is widely expressed in a variety of developing and adult tissues.Fetal Proteins: Proteins that are preferentially expressed or upregulated during FETAL DEVELOPMENT.