PAX5 and leukemia: Similar to the mouse leukemia samples, pharmacological inhibition of PI3K and mTOR using dactolisib (Fig. 7l and Supplementary Fig. 25), or treatment with the SK inhibitors Compound 49 (Fig. 7m) and Compound 55 (Fig. 7n) had a clear inhibitory effect on two primary human diagnostic PAX5 P80R B-ALL samples presenting with IL7R type 1a gain-of-function mutations.