Telomeric transgenes are silenced in adult mouse tissues and embryo fibroblasts but are expressed in embryonic stem cells. - Gao Q; Reynolds GE; Innes L; Pedram M; Jones E; Junabi M; Gao DW; Ricoul M; Sabatier L; Van Brocklin H; Franc BL; Murnane JP (Stem cells (Dayton, Ohio), 2007)