Updated project metadata. he aim of the project is to characterize qualitatively and quantitatively the interaction of cystatin D in other protein partner and the formation of a complex in whole saliva of patients affected by different forms of systemic mastocytosis (SM), with and without skin involvement. The different composition of the complex could be useful to distinguish patients from healthy subject and the different forms of systemic mastocytosis. Pools of whole saliva from SM (SM-C and SM+C) patients, and from sex/age matched healthy controls were submitted to immunoprecipitation assay using cystatin D antibody followed by SDS-PAGE in reducing conditions, tryptic digestion, and nano-HPLC-high-resolution-MS/MS analysis.