rna interference screening identifies a novel role for pctk1cdk16 in medulloblastoma with cmyc amplification medulloblastoma mb is the most common malignant brain tumor in children and is associated with a poor outcome cmyc amplification characterizes a subgroup of mb with very poor prognosis however there exist so far no targeted therapies for the subgroup of mb with cmyc amplification here we used kinomewide rna interference screening to identify novel kinases that may be targeted to inhibit the proliferation of cmycoverexpressing mb the rnai screen identified a set of 5 genes that could be targeted to selectively impair the proliferation of cmycoverexpressing mb cell lines akap12 akinase anchor protein csnk11 casein kinase 1 alpha 1 epha7 eph receptor a7 and pctk1 pctaire protein kinase 1 when using rnai and a pharmacological inhibitor selective for pctk1 we could show that this kinase plays a crucial role in the proliferation of mb cell lines and the activation of the mammalian target of rapamycin mtor pathway in addition pharmacological pctk1 inhibition reduced the expression levels of cmyc finally targeting pctk1 selectively impaired the tumor growth of cmycoverexpressing mb cells in vivo together our data uncover a novel and crucial role for pctk1 in the proliferation and survival of mb characterized by cmyc amplification