Twins and omics: the role of twin studies in multi-omics

Genomics, transcriptomics, proteomics, and metabolomics are the four main omics domains, referring to high-throughput studies of the genome (DNA), transcriptome (RNA), proteome (proteins), and metabolome (metabolites). Together, these omics domains describe how proteins are formed by the transcription and translation of genetic information and how cells, tissues, and organisms’ function at the molecular level. Other omics layers reflect regulatory and modulatory processes or exposures to the environment. Twin designs offer powerful analytical tools to study variation in omics data and the influence of omics on phenotypes and phenotypic development. Here, we review and discuss the contribution of twin studies to omics and argue that twin research plays a valuable role in omics research.