Aged Confetti clones exhibit higher mutational rates than young Confetti clones. Transplanted Conf-VECre BM from aged or young donors was either maintained for 16 months in primary recipients or serially transplanted every 4 months for a total of 16 months. Confetti-sorted clones were subjected to WES. (A) Experimental schematic. (B) WES of aged (n = 7) and young (n = 4) sorted Confetti clones after serial transplantation. Mutation analysis revealed that aged clones accumulated a significantly higher number of mutations than young clones when serially transplanted (*P < .05). (C) WES of aged (n = 4) and young (n = 2) sorted Confetti clones 16 months postprimary transplant. No overlap was observed in mutations detected after primary transplant compared with repeated transplantation (please see supplemental Tables 2 and 3). (B) See Table 1 and “Methods” for experimental details.