COL3A1 and glioma: Compared with normal tissues, Cd4, Spp1 and Col3a1 expression were significantly increased in glioma tissues (Cd4, p < 0.05; Spp1, p < 0.05; Col3a1, p < 0.05; Figure 5B), but their expression levels were not correlated with overall survival (Supplementary Figure S4).