(A) TIL-MDSCs and subpopulations from WT and p53null mice were analyzed (n= 5-10). (B) Proliferating TIL-MDSCs in tumor bearing mice were analyzed as BrdU+CD11b+Gr-1+ cells 24 hours post-BrdU injection. (C) Representative tumor histology images from WT and p53null mice. Scale bar = 100 mm. (D) Representative tumor IHC images (200X) from WT and p53null mice revealing blood endothelial cells (BEC, LYVE-1−Gp38−CD31+), lymphatic endothelial cells (LEC, LYVE-1+Gp38+CD31+), fibroblastic reticular cells (FRC, ER-TR7+Gp38+α-SMA+), and CD11b+ cells. The relative area of CD31+ vasculatures and ER-TR7+ FRC-stroma was determined using a computer-assisted program. Data are mean ± s.e. (n= 3). * denotes a significant difference (p < 0.05).