Proteins have been extracted from kidney calculi with SDS buffer. Proteins were seperated by 1D-SDS-PAGE and stained with coomassie. Each gel lane was cut into 5 (or 6) pieces. Proteins were digested in gel with trypsin. Tryptic peptides were analysed by nanoLC-MS/MS on an ion trap instrument (6340 Ion Trap, Agilent) with CID. Peak lists were generated with Mascot Distiller, and database searching was performed with Mascot. The data from 5 (or 6) LC-MS/MS runs from one patient ware merged into one mgf file, which was searched against IPI (human) database.