IMGT/GENE-DB is the IMGT genome database for IG and TR genes from human, mouse and other vertebrates. IMGT/GENE-DB provides a full characterization of the genes and of their alleles: IMGT gene name and definition, chromosomal localization, number of alleles, and for each allele, the IMGT allele functionality, and the IMGT reference sequences and other sequences from the literature. IMGT/GENE-DB allele reference sequences are available in FASTA format (nucleotide and amino acid sequences with IMGT gaps according to the IMGT unique numbering, or without gaps).