HISTome2 is freely available, knowledge base to display information about histone variants (noncanonical), isoforms (canonical), sites of their post-translational modifications and about various histone-modifying enzymes.

The database covers 5 types of histones, 10 types of their post-translational modifications and 14 classes of modifying enzymes. The current version contains information for about 97 histone proteins (33 variants, 64 isoforms), 114 different PTMs and 164 histone-modifying enzymes. Many data fields are hyperlinked to other databases (e.g. Uniprot, HGNC, Refseq mRNA, Refseq protein, TCGA firebrowse, TargetScanHuman 7.2, etc.). Additionally, this database also provides sequences of promoter regions (-700 TSS +300) for all gene entries. Sites of post-translational modifications of histones and their respective enzymes were manually searched from PubMed listed literature.

This Infobase would be of use to all basic and clinical researchers especially those interested in epigenetic regulation. We welcome suggestions from the scientific community.