CD81 and glioblastoma: Additionally, GBM patient data show other methylated genes, including GATA6 (GATA binding protein 6) (68.4%), CD81 (CD81 antigen) (46.1%), DR4 (Death receptor 4) (41.3%) and CASP8 (Caspase-8) (56.8%) (Skiriute et al., 2012).