TrkA⁺and TrkC⁺MCs infiltrate the gut of patients with SM. Representative immunofluorescence double staining of gut sections (original magnification ×400) of patients with mastocytosis (MAST; n = 4) with an anti-tryptase antibody labeled with Cy-2 (green) and anti-TrkA, anti-TrkB, and anti-TrkC antibodies labeled with Cy-3 (red) overlay pictures of both stainings are shown. White bar = 50 µm.