Stand Up To Cancer (SU2C) and Cancer Research UK (CRUK) are collaborating to support three SU2C-CRUK Pediatric Cancer New Discoveries Challenge teams to accelerate the development of new treatments for some of the rarest and deadliest pediatric diseases. Building on the collaborative, multi-disciplinary model of SU2C grants, three trans-Atlantic teams will do the initial development over two years and then compete for an additional four years of funding to further advance their work.