Tumors were fixed in 10% formalin for 48 hours and paraffin embedded. 4 μm sections were stained with hematoxylin and eosin (H&E), Masson’s trichrome, or Picrosirius red at the University of Washington Histology Core. Primary antibodies used recognized CD163 (Novocastra, 10D6, 1:200), cleaved caspase 3 (Cell Signaling, D175, 1:200), and Ki67 (Thermo Fisher, clone SolA15, 1:200). Slides were scanned using the Nanozoomer Digital Pathology slide scanner (Hamamatsu; Bridgewater, New Jersey), and Visiopharm software (Hoersholm, Denmark) was used to identify regions of interest (ROI, i.e. tumor tissue, excluding normal tissue) sampled at 100%. The software was trained to detect immunoreactivity using a project-specific configuration based on a threshold of pixel values as we previously reported (6 (link)). The number of positively stained cells was measured in 3–5 non-overlapping 20X fields using NIS-Element imaging software (Nikon’s universal software platform, n=3–5 mice per group). Collagen was quantified from 2 tumor sections stained with Picrosirius red, and intensity of the red staining was assessed in a blinded manner across 3–5 20X fields as follows: 0, no staining detected; 1, light staining; 2, moderate; 3, moderate-high staining intensity; 4, high staining, as we previously described (6 (link)) (n= 3–6 animals per cohort).