Neuroblastoma (NB) is a deadly pediatric tumor arising from the sympathetic nervous system, has a low mutational burden but highly recurrent DNA copy number imbalances including 17q gain in most of high-risk cases. With a bioinformatics approach to scrutinize 17q gains for putative dependency genes, we identified BRIP1, a known key player in replication fork dynamics. In this project, we will study the molecular basis of BRIP1 dependency in NB in detail using novel models and explore unstudied BRIP1 functionalities to provide a further basis for drug development efforts. To achieve this, we will (1) map dependency-related BRIP1 functionalities by a drop-out CRISPR screen with a BRIP1 coding region dense sgRNA library in NB cells and perform an in vivo structure-function analysis for six distinct BRIP1 functional domains; (2) study the role of BRIP1 on transcriptional control and the NB epigenome using in vitro and in vivo analysis under conditions of BRIP1 knock down or overexpression. Using RNA-immunoprecipitation, we will deeper explore the proposed (long non-coding) RNA binding capacity of BRIP1; (3) investigate a novel role for BRIP1 in translation based on our observation that BRIP1 overexpression in NB cells rescues eIF4a inhibition and (4) perform in vivo exploration of BRIP1 dependency using a novel zebrafish BRIP1 dTAG-controlled model as drug target validation and test a new compound targeting polymerase theta (POLQ), shown to be synthetic lethal to BRIP1 loss.