In 2020, the U.S. Food and Drug Administration (FDA) approved selumetinib, a selective MEK 1/2 inhibitor, for the treatment of symptomatic, inoperable plexiform neurofibromas (PNs) in pediatric patients with neurofibromatosis type 1 (Figure 1) [9]. The gene discussed is MAP2K1; the disease is paraneoplastic neurologic syndrome.