The term "chromosomics" is introduced to draw attention to the three-dimensional morphological changes in chromosomes that are essential elements in gene regulation. Chromosomics deals with the plasticity of chromosomes in relation to the three-dimensional positions of genes, which affect cell function in a developmental and tissue-specific manner during the cell cycle. It also deals with species-specific differences in the architecture of chromosomes, which has been overlooked in the past. Chromosomics includes research into chromatin-modification-mediated changes in the architecture of chromosomes, which may influence the functions and life-spans of cells, tissues, organs and individuals. It also addresses the occurrence and prevalence of chromosomal gaps and breaks.