dbMHC (www.ncbi.nlm.nih.gov/projects/gv/mhc/) focuses on the major histocompatibility complex (MHC) and contains sequences and frequency distributions for alleles of the MHC, an array of genes that play a central role in the success of organ transplants and an individual’s susceptibility to infectious diseases. dbMHC also contains HLA genotype and clinical outcome information on hematopoietic cell transplants performed worldwide. dbLRC offers a comprehensive collection of alleles of the leukocyte receptor complex with a focus on KIR genes. dbRBC represents data on genes and their sequences for red blood cell antigens or blood groups. It hosts the Blood Group Antigen Gene Mutation Database (37) and integrates it with resources at NCBI. dbRBC provides general information on individual genes and access to the ISBT allele nomenclature of blood group alleles. All three databases dbMHC, dbLRC and dbRBC provide multiple sequence alignments, analysis tools to interpret homozygous or heterozygous sequencing results (38) and tools for DNA probe alignments.
