On the basis of recent research, the roles of MCs in the sensitization and elicitation phases of CHS have been considered as follows: First, during the sensitization phase (which is equivalent to the condition of ICD), MCs are activated directly or indirectly by haptens to release a diverse spectrum of mediators, including histamine and TNF-α, which induce vasodilatation and neutrophil recruitment [53,55]. This evidence concerns the gene TNF and impulse control disorder.