COL3A1 and Ehlers-Danlos syndrome, vascular type: In vEDS, it is known that defective type 3 collagen (COL3A1) weakens vascular endothelium and perivascular ECM, heightening risks of cerebrovascular events (e.g., arterial dissections) and possibly allowing pro-inflammatory cytokines (e.g., IL-6, TNF-α) to breach the CNS (see Figure 2).