NFE2L2 and hepatocellular carcinoma: Moreover, ChIP assays revealed that the expression of Nrf2 significantly affected Sp1 binding to PDGFA promoter in Nrf2 over-expressed or Nrf2-silenced MHCC-97H cells (Figure 4K), indicating that, apart from Sp1, the constitutive level of Nrf2 in HCC cells was mandatory to manipulate PDGFA transcription.