Cell-to-cell variability and gain of methylation at polycomb CpG islands as a hallmark of aging

Nature Communications, Published online: 09 June 2026; doi:10.1038/s41467-026-74118-5 Aging is associated with DNA methylation changes, but how this occurs in individual cells is unclear. Here, the authors show that methylation at polycomb CpG islands accumulates unevenly across single cells, revealing that some cells age faster than others.