At present, NF1 can be diagnosed by the presence of ≥ 2 of the revised diagnostic criteria: ≥ 6 bilateral café au lait macules (CALM), bilateral skinfold freckling, (plexiform) neurofibromas, e.g. (sub-)cutaneous, nerve roots, plexus and/or peripheral nerves, optic pathway gliomas (OPGs), nodules or choroidal abnormalities, bone dysplasia, the presence of a heterozygous pathogenic NF1 variant or the presence of parent with NF1 (Fig. 1; Table 1; [5]). The gene discussed is NF1; the disease is plexiform neurofibroma.