Fig 2: GluR4 protein expression analysis. A Representative blots of GluR4 isoforms in ten CRC paired tissue samples. NaK ATPase was used as loading control. B Box plots of GluR4 long and short expression in normal vs tumour samples. C Box plots of GluR4 isoforms within tumour and normal samples groups. Asterisks indicate statistically significant differences (*p value < 0.05, **p value < 0.01)

Fig 3: GRIA4 gene expression analysis. A Box plot fold change values of GRIA4 long (on the left) and short (on the right) for normal and tumour tissues comparison. B Box plot fold change values of GRIA4 variants comparison within tumours and normal colon tissues. Asterisks indicate statistically significant differences (**p value < 0.01, ***p value < 0.001)

Fig 4: Methylation values obtained from our colorectal (CRC) discovery set and The Cancer Genome Atlas (TCGA) validation set. Genomic organization of GRIA4 (A) and VIPR2 (B), including the localization of exons and CGIs. Mean ß values, resulting from the average of the samples (normal and tumour) of each probe mapping on the altered CGIs associated with GRIA4 (A) and VIPR2 (B). When more than one CGI is shown, the altered one is enclosed in a yellow box.

Fig 5: Genomic organisation of GRIA4 including the localization of exons and CGI. Mean beta values resulting from the average of the samples (normal and tumour) of each probe mapping on the whole gene [1]. The zoom in focuses on the CGI located at the promoter region