The present disclosure relates to a human CK8 antigen peptide, an antibody, or antibody fragment thereof, or a humanized antibody, specifically binding the peptide having the amino acid sequence of SEQ ID No. 29, a fragment of CK-8. Said molecules can be used use in the detection and/or treatment of tumors whose cells express CK8 protein, in particular the peptide of sequence according to SEQ ID No.29, on their surface.