DNMT3A and cyclic hematopoiesis: CH is an age-related phenomenon as mutations are acquired over time, affecting ∼10% of those over the age of 65 years in population studies.304 Age is also strongly associated with the presence of CH in most reported disease cohorts, as well as being a predictor of accelerated clonal growth.305 The most frequently identified mutations are in DNMT3A and TET2 genes, genes which encode enzymes responsible for methylating and demethylating DNA CpG sites, respectively.