There have been various in vivo studies that have suggested fibrate exposure may be protective for brain tumours, specifically gliomas, by modulating PPAR-α inhibition.23–26 There is similar evidence available for the consideration of glitazones as a treatment option from in vivo studies.27–30 However, prior to this study there have been no other pharmacoepidemiological studies that examined whether fibrates or glitazones affect brain tumour risk. This evidence concerns the gene PPARA and brain neoplasm.