TGFB1 and central nervous system cancer: In addition, both TGFB1 and TGFB2 ligands were upregulated in these tumors compared to normal brain tissue (TGFB1 mRNA expression showed a significant (p < 0.0001) 4.1-fold increase, and TGFB2 mRNA showed a significant (p < 0.0001) 2.2-fold increase in LGG tumors), suggesting that TGFB ligands are pivotal in establishing an immunosuppressive, angiogenic, and pro-tumorigenic TME in gliomas mediated through TAMs.