LysMCreMtorfl/fl mice were transplanted with BALB/c hearts, and treated with CTLA4-Ig alone or together with a blocking anti-PD-L1 mAb. For assessment of chronic rejection, two surviving grafts were harvested from CTLA4-Ig treated mice at day 28 post-transplantation, and four rejected grafts were harvested from CTLA4-Ig and anti-PD-L1 treated mice on days 36, 43, 44 and 47. (A) Percentage of heart allograft survival after transplantation. ** p < 0.01; log-rank test. (B) Representative images of H&E and VVG stained sections of grafts harvested from indicated groups. Scale bar = 100 μm; ×400 magnification. (C) Morphometric quantification of neointimal index in indicated groups.