BRAF and Langerhans cell histiocytosis: Some common potent oncogenic drivers, such as BRAF point mutations, do not always predict response to a relevant targeted agent across adult tumour types,2 but promising results in a variety of paediatric V600E mutated tumours (high- and low-grade glioma, papillary thyroid cancer, Langerhans cell histiocytosis, melanoma) raise the intriguing question of whether BRAF inhibitors may be tumour agnostic in children.