COL4A2 and glioblastoma: The outcome revealed that COL4A1 and COL4A2 effects on immune infiltration had a highly similar association with HMGA2 in both GBM and LGG patients, especially on Th2 cells, macrophages cells and pDC cells infiltration (r = 0.68, 0.65 and −0.39 for COL4A1, r = 0.66, 0.64 and −0.37 for COL4A2 in GBM).