Tianliang Sun, Stefano Annunziato, Jan S. Tchorz www. aging-us. com 4685 AGING may highlight mechanisms restricting proliferation of AXIN2+ pericentral hepatocytes during homeostasis. Back-to-back with our study, two other reports provided important insights into clonal expansion of hepatocytes in different zones and their plasticity during homeostasis and repair [7, 8]. Using AAV-induced random confetti lineage tracing, Holger Willenbrings group showed that proliferation of hepatocytes in all zones maintains the hepatocyte mass during homeostasis and enables liver repair in response to various insults [7]. Markus Grompes team clarified that polyploid hepatocytes have extensive regenerative capacity using a multicolor reporter allele system to genetically label and trace poly-