MCT4 upregulation is sufficient to induce normal cell growth. (A-C) Ex vivo pHi analysis by pHrodo Red (A), donor cell chimerism (B), and in vivo BrdU incorporation assay (C) of HSPCs in BM with MCT4 or NHE1 OE at secondary transplantation examined by FACS (n = 3-5). (D) In vivo glucose uptake in mouse HSPCs with MCT4 OE (n = 3). (E) ECAR and OCR of Lin⁻ BM cells with MCT4 OE in vitro (n = 3). (F) In vitro intracellular metabolite profiling by GC/LC-MS showing the relative levels of metabolites in Lin⁻ BM cells with MCT4 OE (n = 3). (G) Percentage of different subpopulations. (H) Ex vivo pHi analysis by pHrodo^TM Red and (I) in vivo BrdU incorporation assay of CB HSPC in BM with MCT4- or NHE1-OE (n = 5). (J) In vitro cellular growth of MC3T3 (n = 5) and CD1 (n = 3) upon MCT4-OE. (K) In vitro pHi analysis of MC3T3 (n = 3) and CD1 (n = 3) by SNARF-1 upon MCT4-OE. *P < .05, **P < .01, ***P < .001. AMP, adenosine 5′-monophosphate; HSC, hematopoietic stem cell; UMP, uridine 5′-monophosphate.