Receptor for members of the ephrin-A family. Binds to EFNA3, EFNA4 and EFNA5. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Mainly expressed in testis. The protein kinase domain is predicted to be catalytically inactive. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the protein kinase superfamily. Tyr protein kinase family. Ephrin receptor subfamily. Truncated N-terminus.