MEG3 and pituitary tumor: GTL2 promoter and intergenic DMR hypermethylation was associated with transcriptional silencing of GTL2 and treatment with 5-AzaC resulted in re-expression of GTL2. Recently, an isoform of GTL2, MEG3a, was reported to be expressed highly in normal pituitary and brain and in other tissues including adrenal (Zhang et al, 2003), but not in many pituitary tumours.