ZFX (Zinc finger protein, X-linked), a key factor that controls the self-renewal of ESCs, belongs to the ZFY family whose members (ZFX, ZFY, ZFA) have similar molecular structures. Mammalian ZFX contains an acidic transcriptional activation domain, a nuclear localization signal (NLS) sequence, and a DNA binding domain consisting of 13 C2H2 zinc fingers. Knocking out ZFX has been shown to impair the self-renewal capacity of mouse ESC and tissue-specific adult stem cell such as hematopoietic stem cells (HSCs) without affecting their differentiation, and ZFX overexpression has been shown to promote ESC self-renewal by impeding differentiation. It's reported that t the 130 kDa band was N-glycosylated, and such a posttranslational modification (PTM) may control the nuclear import of ZFX, 91 kDa may be the non-N-glycosylated subtype which was lowly expressed. (PMID: 23322077, PMID:24228108)