YY2 and neoplasm: Furthermore, transmission electron microscopy revealed increases of dysfunctional, “spaghetti‐like” appearance of mitochondria in stem‐like tumor spheres formed by HCC‐LM3 cells overexpressing YY2 (Figure 4E; Figure S7A, Supporting Information), and more fragmented, less tubular mitochondria in those formed by HCC‐LM3YY2KO cells (Figure S7B, Supporting Information), indicating that YY2 increased dysfunctional mitochondria.