G, Resorption rate was reduced on day 8 in Groups 1 (n=41 different implantation sites) and 2 (n=30 different implantation sites), but not in Group 3 (n=40 different implantation sites). The same data of Rb1f/f and Rb1d/d mice without P4 treatment in Fig 2I were used. H&E staining was performed using all sections that shows the implantation sites, and resorption rate was evaluated. *P<0.05 vs Rb1f/f mice; **P<0.05 vs Rb1d/d mice; Fisher's exact test. 