SPHK1 and leukemia: Previous work from our laboratory showed that actinomycin D (Act‐D) induces SK1 degradation in Molt‐4 T‐cell leukemia cells, and this degradation is rescued in Molt‐4 cells overexpressing the papilloma virus E6 protein, which targets p53 to degradation, suggesting that SK1 proteolysis is p53 mediated.