Updated project metadata. Physiological functions of periodontal ligament (PDL) include anchorage, force absorption,and proprioceptive information. Despite the knowledge about biology of PDL cells, there is a lack of information regarding the molecular signature of permanent (PermPDL) and deciduous (DecPDL) PDL tissues. The present study was designed to characterize the membrane proteome of DecPDL and PermPDL primary cells (n=6) by a label-free quantitative proteome.