Increased TM in CCM. (A) Immunofluorescence staining of TM (red) and collagen IV (Col IV; green) of human CCM lesion-free brain tissue matched to the CCM patient (2 samples) and brain tissue from a healthy subject (Control). Asterisks denote vascular lumen of CCM lesions. Scale bar, 100 μm (n = 4). (B) Expression levels of THBD, as assessed by RNA sequencing of endothelial cells isolated from human CCM lesions (SEM, n = 5). (C) Plasma levels of soluble TM in patients with sporadic CCM (SEM, n = 38), CCM1 (SEM, n = 21), or CCM3 (SEM, n = 18), as well as normal controls (SEM, n = 10). **P < .01, ***P < .001, unpaired 2-sample t-test.