New CH risk loci included the PARP1 coding variant rs1136410, where the G allele is protective for DNMT3A-CH and associated with reduced catalytic activity53 suggesting that this most common form of CH may be vulnerable to PARP inhibition, in keeping with the observed synergy between PARP and DNMT inhibitors86. The gene discussed is DNMT1; the disease is cyclic hematopoiesis.