... of their target genes.Indeed, several examples of feedback regulation thatinvolve miRNAs have been reported. Below, we attemptto summarize our recent understanding of feedback regulation of ... expression of estrogen receptor-a(ERa) is autoregulated by miR-18a, -19b and -20b,which in turn are upregulated by the activation of ERa. This mechanism of regulation provides a widerange of coordinated ... large number of genes appear to be the target of miRNAs, and an essential role formiRNAs in the regulation of various conserved cell signaling cascades,such as mitogen-activated protein kinase,...