MGMT and glioblastoma: In all the GBM patients, TGFB2 methylation was positively correlated with TGFB1 (r = 0.35, p < 0.0001), TGFB3 (r = 0.22, p = 0.0002), and MGMT (r = 0.21, p = 0.0003) methylation and negatively correlated with the age at diagnosis (r = −0.3, p < 0.0001) (Figure S3A).