For instance, the highly specific PI3K inhibitor GDC-0941 reduced CD133+ stem-like MB cell numbers and their clonogenicity and also delayed the growth of highly aggressive group 3 MBs in a xenograft model,114 while celecoxib improved the chemoradiosensitivity of CD133+ MB xenografts.115 Given that miRNAs act upstream of these pathways, they represent attractive candidate targets against the most difficult to eradicate component of the disease and might have particular value in recurrent disease that has failed conventional therapy. This evidence concerns the gene PROM1 and Mobius syndrome.