TGFB1 and glioma: In particular, the pathways of TGF-β and WNT are highly correlated with the process of fibrosis [33,35,37], and both pathways’ activities are elevated in the two fibrotic clusters, “fibrotic” and “immune-enriched, fibrotic”, suggesting that these pathways would be intrinsic mechanisms for the fibrotic phenotype in glioma, thus requiring further exploration.