Different somatic NF1 mutations (frameshift insertion in breast cancer (p.A985fs), missense mutation in MPNST (p.G23R), and inframe deletion in dermal neurofibroma (p.L1876del‐Inf)) were detected in all three tumors investigated; suggesting the importance of second‐hit aberration in NF1 for tumorigenesis. This evidence concerns the gene NF1 and dermal neurofibroma.