Updated publication reference for PubMed record(s): 35269711. Mesenchymal stromal stem cells (MSCs) gain increasing focus in the field of regenerative medicine due to their differentiational abilities into chondrocytes, adipocytes and osteoblastic cells. However, it is apparent that the transformation processes are extremely complex, cause cellular heterogeneity and need further insights into functional annotation. The aim of the study was to characterize differences between MSCs and cells after adipogenic or osteoblastic differentiation at the proteome level. For this, we analysed the proteome of isolated and cultured MSCs and after differentiation into adipogenic and osteoblastic cell lineages using electrospray ionization tandem mass spectrometry in data-independent acquisition mode. Protein inference and quantification was performed using deep neural networks in library free mode. By jointly using strict differential expression analysis and machine learning algorithms, two cell type specific marker protein panels for the osteoblastic and the adipocytic lineage were identified which allow for distinguishment of the three cell types.