On the contrary, in the case of PTEN, we could not see a reduction of mRNA expression in GOS3 and MOG-G-CCM cells, which had previously shown to be hypermethylated for this gene; however, they both had just one methylated allele, the other one remaining free of methylation, which might be enough to maintain normal PTEN expression levels. Here, MOG is linked to cerebral cavernous malformation.