Mutation frequencies and patterns. At time of transplantation, 91% of patients had at least 1 mutation, and the median number of mutations was 3 (range, 0-8 mutations). (A) The most frequently mutated genes were SRSF2 (34.5%), TET2 (34.2%), ASXL1 (34.2%), RUNX1 (20.3%), NRAS (19.3%), DNMT3A (17.4%), SETBP1 (16.0%), CBL (15.4%), U2AF1 (14.4%), ZRSR2 (11.2%), KRAS (10.9%), EZH2 (9.0%), IDH1 (7.9%), SF3B1 (8.0%), JAK2 (7.8%), and TP53 (6.9%). A significant association was found for TET2 and ASXL1 (P = .01), showing co-occurrence of both mutations in 16% of patients. (B) In line with previous findings,¹⁵  another association was found for TET2 and RNA splicing factors (P = .001), showing co-occurrence of TET2 and SRSF2 in 17% of patients.