That same study draws attention to the discrepancy in mast cell count figures according to the different stains used: while in cases of proven mastocytosis, the median mast cell density was almost equal with trypsin and CD117 at any cutaneous level (overall, subepidermal, intermediate and lower dermis), in the control group, those values were notoriously dissimilar, with a median four or more times higher with the use of tryptase than with CD117. This evidence concerns the gene KIT and mastocytosis.