Staining with MitoTracker Red, a ΔΨm‐dependent mitochondria marker, and MitoTracker Green, a ΔΨm‐independent mitochondria marker, revealed that YY2 overexpression clearly reduced ΔΨm in stem‐like tumor spheres formed by HCC‐LM3 and MHCC‐97H cells (Figure 4F; Figure S7C, Supporting Information). Here, YY2 is linked to hepatocellular carcinoma.