Eps15 homology domain-containing protein 3, abbreviated as EDH3 and also known as PAST3, is a protein encoded by the EHD3 gene. The Eps15 homology (EH) domain-containing protein family consists of four members, EHD1, EHD2, EHD3, and EHD4. The chromosomal locations of the human EHD genes are as follows: EHD1 maps to 11q13, EHD2 maps to 19q13.3, EHD3 maps to 2p21, and EHD4 maps to 15q11.1 (1-3). The encoded proteins of all EHD family members contain multiple conserved regions, which include an amino-terminal nucleotide-binding consensus site, a bipartite nuclear localization signal, and a carboxy-terminal EH protein-binding domain with an EF-hand motif (3,4). EHD1 is ubiquitously expressed with increased expression in testis (2,3). EHD2, EHD3, and EHD4 have more specific expression with EHD2 highly expressed in heart, EHD3 expressed in brain, kidney, liver, placenta, ovary, and heart, and EHD4 expressed in heart, placenta, and pancreas (1,5,6). The EHD proteins may participate in ligand-induced endocytosis (3-5).