ASXL1 and cyclic hematopoiesis: One possible explanation is that environmental factors have a greater influence on ASXL1-CH and PPM1D-CH than on other CPLD-CH types— risk of PPM1D-CH was substantially increased in patients who have undergone chemotherapy (OR = 7.9, P = 4.5 × 10−4; Supplementary Table 13), while ASXL1-CH was more strongly associated with smoking than other CPLD-CH types (Supplementary Table 14) in agreement with previous reports9,45,46.