Citing this page:
Elemento, O. and Lefranc, M.-P. "IMGT/PhyloGene: an online software package for phylogenetic analysis of immunoglobulin and T cell receptor genes", Dev. Comp. Immunol., 27, 763-779 (2003) PMID: 12818634
Lefranc, M.-P. and Lefranc, G. "The Immunoglobulin FactsBook" Academic Press, London, UK (458 pages) (2001) ISBN: 012441351X
A clan is a set of subgroups, eventually from different species, which appear related on phylogenetic trees
(IGHV, IGKV, IGLV clans).
The 'clan' concept is part of the 'CLASSIFICATION' concept of IMGT-ONTOLOGY .
IMGT clans correspond to the categorization of variable gene subgroups based on nucleotide sequences similarity of the FR-IMGT .
IMGT/PhyloGene allows to perform directly clan analysis for the human and mouse genes  or for any variable nucleotide region provided with gaps according to the IMGT unique numbering.
IMGT/PhyloGene analysis does not include pseudogenes for which FR-IMGT and CDR-IMGT delimitations are not defined.