Increased serum levels of NGF-β, NT-3, and NT-4 in patients with mastocytosis. NGF-β (A), BDNF (B), NT-3 (C), and NT-4 (D) serum levels of healthy control participants (CTR; n = 50 for NGF-β, NT-4; n = 33 for BDNF; n = 40 for NT-3) and patients with mastocytosis (MAST; n = 49 for NGF-β, NT-4; n = 33 for BDNF; n = 39 for NT-3). ASM (n = 2 for NGF-β; NT-3, NT-4; n = 1 for BDNF), SM-AHNMD (n = 1 for all NTs), MIS (n = 11 for NGF-β, NT-4; n = 6 for BDNF; n = 5 for NT-3); CM (n = 8 for NGF-β, NT-4; n = 6 for BDNF; n = 6 for NT-3); ISM (n = 27 for NGF-β, NT-4; n = 25 for NT-3, n = 19 for BDNF), ISM with skin involvement (ISM*) (n = 20 for NGF-β, NT-4; n = 19 for NT-3, n = 13 for BDNF), SSM (n = 3 for all NT), and IBMM (n = 4 for NGF-β, NT-4; n = 3 for BDNF, NT-3).