YY2 and hepatocellular carcinoma: YY2 overexpression increased the proportion of HCC‐LM3 and MHCC‐97H stem‐like tumor spheres containing elevated green fluorescence or cells with dysfunctional mitochondria (Figure 4H; Figure S7E, Supporting Information); whereas YY2 knock‐out decreased them (Figure 4I; Figure S7F, Supporting Information).