Provided are age-modified cells and method for making age modified cells by reducing or increasing the level of genomic nucleic acid methylation in the cells. The aging and/or maturation process can be accelerated or reduced and controlled for young, aged, mature and/or immature cells, such as a somatic cell, a stem cell, a stem cell-derived somatic cell, including an induced pluripotent stem cell-derived cell, by reducing or increasing the level of genomic nucleic acid methylation in the cells. Methods described by the present disclosure can produce age-appropriate cells from a somatic cell or a stem cell, such as an old cell, young cell, immature cell, and/or a mature cell. Such age-modified cells constitute model systems for the study of late- onset diseases and/or disorders.
