A) Methylation levels of two CpGs from 27K methylation array (Illumina) present in the promoter region of GNG4 in three datasets – our patient set, GSE22867 and TCGA, B) RNA level expression of GNG4 in TCGA and Rembrandt datasets, C) RNA level of GNG4 in GBM cell lines as compared to immortalized normal human astrocyte cell line, SVG, D) Bisulphite sequencing of the promoter region of GNG4 encompassing 36 CpG islands in control brain, GBM tissue and GBM cell lines. The percentage of methylation in all CpGs of the GNG4 promoter sequence has been given at the right side of each sample. The average percentage methylation of the CpG covered in Illumina Infinium Array has been provided near the box corresponding to that CpG. BSC refers to the bisulphite converted region that is subjected to sequencing, E) RNA level of GNG4 after treatment of GBM cell lines with DNA methyltransferase inhibitor, Azacytidine (Aza). p-value was calculated by Student’s t test where *, ** and *** represents p-value of < 0.05, < 0.01 and < 0.001 respectively.