CHIP is driven by somatic mutations in leukaemia driver genes, such as Janus Kinase 2 (JAK2), Tet methylcytosine dioxygenase 2 (TET2), ASXL Transcriptional Regulator 1 (ASXL1) and DNA (cytosine-5)-methyltransferase 3A (DNMT3A), leading to reduced diversity of the blood pool. The gene discussed is TET2; the disease is leukemia.