Antibody Panel Packs for investigating histone modifications, including panels for histone H3 and H4 methylation, histone H3 and H4 acetylation, and histone H3 phosphorylation. Modulation of chromatin structure via histone modification plays an important role in the regulation of transcription in eukaryotes. Euchromatin, or loosely packed chromatin, is associated with gene expression, whereas tightly coiled chromatin, or heterochromatin, is associated with gene silencing. Panels include site modifications and functional modifications, such as those related to active genes and repressor genes.