NF1 and skin neoplasm: Notably, NF1 is biallelically inactivated in most tumors developing in NF1 patients and, based on The Cancer Genome Atlas (TCGA), it is also genetically altered with a frequency up to 82% in a variety of sporadic tumors, particularly MPNST and skin cancers, including desmoplastic melanoma, skin squamous cell and basal cell carcinoma, and cutaneous melanoma, but also, among others, glioblastoma and ovarian high-grade serous carcinoma (Figure 2) [29].