GJA1 and central nervous system cancer: Interestingly, the decrease in Cx43 expression is proportional to tumour grade and proliferative capacity (Pu et al., 2004), and is not due to a reduced genetic transcription: grade III and IV gliomas indeed present elevated Cx43 mRNA but low proteins levels (Caltabiano et al., 2010), suggesting an alteration in post-transcriptional mechanisms in glioma astrocytic cells.