In a groundbreaking study, US researchers have unlocked a new frontier in the fight against ageing and age-related diseases. The study, conducted by a team of scientists at Harvard Medical School and Massachusetts Institute of Technology (MIT), has published the first chemical approach to reprogramme cells to a younger state. Previously, this was only achievable using a powerful gene therapy. The findings, published in the journal Aging-US, builds upon the discovery that the expression of specific genes, called Yamanaka factors, could convert adult cells into induced pluripotent stem cells (iPSCs). The discovery, which won the Nobel Prize in 2012, raised the question of whether it might be possible to reverse cellular ageing without causing cells to become too young and turn cancerous. In the new study, the researchers screened for molecules that could, in combination, reverse cellular ageing and rejuvenate human cells. They developed high-throughput cell-based assays to distinguish young cells from old and senescent cells, including transcription-based ageing clocks and a real-time nucleocytoplasmic protein compartmentalisation (NCC) assay.