Nobel laureate Sharp PA has reported that "Let-7 represses Nr6a1 and a mid-gestation developmental program in adult cells"

Dr L Boomianthan PhD, Chief-Scientist-cum-Director of GBMD, reports that p53/p63/p73 promotes continual suppression of embroyonic gene expression in adult cells by regulating the Let-7-Nr6a1 pathway through its target genes. 

http://genomediscovery.org/interrupting-the-mid-gestation-developmental-program-p53p63p73-promotes-continual-suppression-of-embroyonic-gene-expression-in-adult-cells-by-regulating-the-let-7-nr6a1-pathway/