Particularly, we observed that the MCTC (Mast Cells with both Tryptases and Chymases positive) marker genes CMA1 is significantly down-regulated in PP (p-value < 0.05), again suggesting the dynamics of mast cell states in psoriatic skin may contribute to the pathogenesis of psoriasis (Figure 5A) (34). Here, CMA1 is linked to psoriasis.