PPM1D and cyclic hematopoiesis: We generally observed the same pattern when analyzing CH genes individually, with significantly increased risk in UKB versus MCPS of CH driven by mutations in each of the five most common genes (DNMT3A, TET2, ASXL1, PPM1D and TP53) as well as JAK2 and SRSF2. Focusing on the two most common CH genes, DNMT3A and TET2, the difference in magnitude of increased risk in UKB was particularly marked (OR = 1.99, 95% CI = [1.90, 2.09], P = 1.34 × 10−171 and OR = 1.48, 95% CI = [1.38, 1.58], P = 1.22 × 10−30 for DNMT3A and TET2, respectively).