Oral lichen planus (OLP) is a chronic inflammatory, autoimmune-mediated disease of the oral mucosa and is classified as a potentially malignant lesion. Patients often suffer from pain and a burning sensation of the oral mucosa, which significantly impairs their quality of life. The etiology remains largely unclear, and there are no causal treatments available. Recent approaches aim to specifically modulate the inflammatory cascade using Janus kinase inhibitors (JAKi). The goal of this project is to characterize the immunological signature of OLP and to analyze the local effects of JAKi therapy. For this purpose, human oral mucosal tissue from healthy individuals and those with OLP will be systematically examined using imaging mass cytometry (IMC). In this way, this project will contribute to research on the pathogenesis of OLP and to the differentiated evaluation of the immunomodulatory effects of JAKi in oral tissue.