YY2 and neoplasm: Meanwhile, in vivo limiting dilution assay (LDA) performed by xenograft experiment using a series of cell amounts as indicated revealed that YY2 overexpression decreased liver CSC frequency by > 10‐fold (Figure 2J,K), as well as the expression of CSC markers CD44 and EpCAM in the xenografted tumor lesions (Figure 2L; Figure S5C, Supporting Information).