PCNA and neoplasm: Immunostaining analysis for PCNA showed a lower number of proliferating hepatocytes in the tumor and non-tumor regions of Atg7/Hmgb1ΔHep livers than those in the Atg7ΔHep livers (Fig. 5a), suggesting that HMGB1 contributed to an overall enhanced proliferation status in autophagy-deficient livers.