Updated project metadata. Decreased salivary flow rates and/or changes in protein composition reported after autologous hematopoietic stem cell transplantation (ASCT) reduces the protective function of saliva. This might be associated with the development of oral mucositis (OM), an inflammation of the oral mucosa as a result of chemotherapy before ASCT which affects patients? quality of life and risk factor for systemic infections. In this study, a TMT-labelled proteomics experiment, a label-free quantification (LFQ) proteomics experiment and a DIA-MS proteomics experiment were used to identify differences in the salivary proteome between patients with ulcerative OM (uOM; WHO score ? 2) and those without (nOM). For the TMT-labelled experiment, saliva samples of 5 uOM and 5 nOM were pooled at different time points: baseline, 1, 2, and 3 weeks after ASCT and 3 months after ASCT. A different salivary proteome was suggested by a distinct clustering of the OM pools at baseline, week 2 and week 3 after ASCT.