TP53 and T-cell non-Hodgkin lymphoma: To determine whether the sphingolipid rheostat is similarly perturbed in a context where Runx1 has established in vivo oncogenic function [Blyth et al., 2001; Shimizu et al., 2013], we introduced Runx1 into two independently derived p53‐null T cell lymphoma lines (Fig. 1A).