ANNOTATION: Translation in all open reading frames (ORF) of human ceruloplasmin (Cp) pseudogene revealed the only translating sequence of 984 nucleotides. The amino acid sequence contains a signal peptide for mitochondrial protein import at N-terminus. The predicted protein without taking the signal peptide into consideration has 92% identity to the corresponding Cp fragment. It contains 20 amino acid substitutions, 8 of them are significant. There is His-X-His motif in the center of a molecule that is typical for copper containing oxidases. Potential copper-binding site appears as a result of the substitution P923H along human Cp sequence. Cp pseudogene transcription product was found in the cultured human cell lines HepG2 and HuTu 80 using RT-PCR strategy. Cp polypeptides with molecular weight of nearly 30 kDa were found in mitochondria of HuTu 80 cells. The possible biological role of mitochondrial Cp is under discussion.