NFE2L2 and hepatocellular carcinoma: Recent data indicate that NRF2 can in turn promote p21 expression in A549 cells, through direct binding on highly conserved sites within the p21 promoter [209] or by indirect modulation prompted by SP1 recruitment and platelet-derived growth factor A- (PDGFA-) dependent activation of the AKT/p21 pathway in HCC [14].