STUB1 and leukemia: Importantly, while donor derived leukemia can occur at low rates, typically from donor CHIP with TP53 or splicing factor mutations or from donors carrying germline DDX41 mutations [61], donor‐engrafted CHIP after allo‐HSCT associates with decreased risk of disease relapse but does not affect overall survival, progression‐free survival or non‐relapse mortality [58].