Deletion of p21 partially restores proliferation of DDB1-deficient hepatocytes and alleviates OC activation.

<p>(A) Western blot for some substrates of DDB1-Cul4A ubiquitin ligase using lysates of hepatocytes isolated from <i>DDB1^F/F</i> and <i>DDB1^F/F;Alb-Cre^+/+</i> mice. (B) Western blot for DDB1 and p21 using lysates of cytoplasmic fraction (C) and nuclear fraction (N) prepared from MEFs. (C) IHC staining for DDB1 and Ki67 on liver sections from <i>DDB1^F/F;Alb-Cre^+/−, DDB1^F/F;p21^−/−</i> and <i>DDB1^F/F;Alb-Cre^+/−;p21^−/−</i> mice. (D) Co-IF staining for A6 and DDB1 on <i>DDB1^F/F;p21^−/−</i> and <i>DDB1^F/F;Alb-Cre^+/−;p21^−/−</i> liver sections. Arrows in <i>DDB1^F/F;Alb-Cre^+/−;p21^−/−</i> mice indicate A6 positive oval cells.