NOS1 and constipation disorder: The lop-induced constipation institute of cancer research (ICR) and Sprague Dawley (SD) model showed a decrease in two ICC markers (C-kit and SCF), an increase in two enteric-nerve-related factors (transient receptor potential vanilloid 1 (TRPV1) and NOS), and a decrease in the other enteric-nerve-related factors (PGP9.5, Brain-derived neurotrophic factor (BDNF), and GNDT) [43,44].