FDX1 and neoplasm: Tumor cells shift their energy metabolism toward glycolysis because of impaired aerobic respiration.[31, 32, 33] Our findings demonstrated that phosphorylated FDX1 increased the extracellular acidification rate (ECAR), whereas FDX1‐WT or the FDX1‐S63A mutations resulted in a lower ECAR (Figure 5H).