While preclinical mouse and pig models of NF1-associated optic pathway glioma (NF1-OPG [7, 29, 70]) and BRAF-driven [20] sporadic pediatric LGGs have helped elucidate the pathobiology of these tumors and served as platforms for therapeutic drug testing [22, 34], they only partially capture the essential properties of their human counterparts. The gene discussed is NF1; the disease is optic pathway glioma.