Prof Dr Peter Findeisen is a specialist in laboratory medicine and Head of Laboratory Diagnostics at MVZ Labor Dr Limbach & Kollegen in Heidelberg. The topic of his lecture at the ISAS Colloquium on July 20, 2025, is "MS-based targeted protein quantification in laboratory medicine". Using selected examples such as the determination of apolipoproteins, he will discuss the advantages and disadvantages of MS-based and immunological analysis methods as well as possible future integration of MS-based protein quantification in medical laboratories.