In 64% of patients with documented cytopenias post-PRRT, clonal expansion of mutant DNA damage response genes (TP53,CHEK2, andPPM1D) were seen, most commonly in PPM1D and TP53 genes.13The data from the Peter MacCallum group, using NGS myeloid amplicon gene panel, also showed mutations in TP53 being the most frequent one in patients developing t-MN.10However, before CH detection can be employed in routine clinical protocols, certain factors about standardization/definition of CH need to be addressed. The gene discussed is PPM1D; the disease is cyclic hematopoiesis.