Quantitative protein array results of sera from 41 healthy controls and 104 patients with neurofibromatosis type 1 (NF1) subdivided into three groups. These comprised 35 patients with NF1 with no plexiform neurofibromas (PNF) and no malignant peripheral nerve-sheath tumors (MPNST) (cutaneous neurofibromas; cNF), 39 patients with NF1 with PNF and no MPNST, and 30 patients with NF1 with MPNST. (A) Insulin-like growth factor binding protein (IGFBP)1 and (B) Regulated upon activation, normal T-cell expressed and secreted (RANTES). (C) IGFBP1 serum concentrations in patients with NF1 with different internal tumor loads as measured by MRI-based volumetry (0 cm3 = no load, 1 to 99 cm3 = small load; 100 to 500 cm3 = modest load; >500 cm3 = high load). Statistical analysis was performed using the non-parametric Mann–Whitney U-test, including Bonferroni correction (*P≤0.05; **P≤0.01; ***P≤0.001).