Dendrogram showing amino acid sequence relationships among the ZIP family members. GenBank accession numbers for sequences designated by name are as follows: IRT1, U27590; IRT2, T04324; ZIP4, U95973; IRT3, M35868; ZRT1, P32804; and ZRT2, X91258. The amino acid sequence of human 998569 is only available in the Entrez database. The Oryza sativa D49213, IRT2, IRT3, and Homo sapiens H20615 clones have not been sequenced completely.