COL4A2 and glioblastoma: As shown in Figure 4A, the high expression of COL4A1, COL4A2 and COL4A6 or the low expression of COL4A3 and COL4A4 can significantly increase the overall survival (OS), disease specific survival (DSS) and progress free survival (PFS) (p < 0.01) of GBM and LGG patients (Figure 4A).