SLC9A1 and acute myeloid leukemia: Kinase inhibitors including quizartinib and ibrutinib reduced NHE1 phosphorylation and pHi in kinase-mutated AML cell lines and such responses were ameliorated by NHE1 mutations at sites critical for its phosphorylation, suggesting a direct mechanistic link between kinase activation, NHE1 phosphorylation, and activation.