NGF and Schnyder corneal dystrophy: A murine model of SCD underscored the importance of mast cell activation, infiltration and NGF in pain hypersensitivity by showing that tryptase, secreted by mast cells, promotes release of substance P and CGRP in DRG (targets of NGF), and inhibition of mast cell activation by imatinib resulted in reduced musculoskeletal pain behaviors and reduced activation of neurons in the DRG (92).