IL1RL1 and leukemia: Since IL1RL1 is expressed in normal HSCs12,13, we interrogated if IL1RL1 is expressed in total LSCs defined as CD34+CD38− in the Princess Margaret leukemia biobank25 (n = 54) and showed that IL1RL1 expression is higher on LSCs as compared to HSCs, which was verified in an independent dataset26–29 (Fig. 1H).