IHC testing and RT-qPCR in patients with LP and morphea cGVHD. (A) TREM-1 IHC labeling of skin biopsies of LP (left panels) chronic graft-versus-host disease (cGVHD), morphea cGVHD (middle right panels), and healthy controls (right panels). Abdominal aorta atherosclerosis was used as positive control. Scale bar, 200 mm for panels at ×20; scale bar, 100 mm for panels at ×40; arrows indicate some of the TREM-1⁺ macrophages. (B) Bar graph showing TREM-1 mRNA expression by using RT-qPCR in healthy controls (n = 5), lichen cGVHD (n = 6), and morphea cGVHD (n = 5). *P < .05.