Collagens type I (COL1A1, COL1A2), III (COL3A1) and VI (COL6A2, COL6A3) were highly upregulated in gliosarcomas, as seen in Figure 4C. The collagen-signature is reflected in the functional analysis of the groups of genes differentially expressed between GBMs and gliosarcomas, as “focal adhesion” is one of the discriminating groups (Table 3). The gene discussed is COL3A1; the disease is gliosarcoma.