COL8A1 and glioblastoma: Of particular interest was that the largest module (IV) of 15 proteins was centrally linked by COL6A2, COL8A1 and CTHRC1, a triangular interactive network of collagen-related proteins that were all overexpressed in GBM and have previously been reported as correlating with increasing tumor cell invasion, migration and adhesion in GBM (Table 3, Figure 4) [10,39,42].