The aim of this project is to develop a diagnostic test for lung mesothelioma based on proteins present in blood plasma. Specifically, we will look for proteins that are released when lung cells are damaged as a result of cancer development. From our previous research we have been able to demonstrate that with our highly sensitive proteomics technique we can distinguish patients with lung mesothelioma from healthy individuals based on different proteins. Before the clinical utility of this panel of proteins can be tested in a clinical trial, our results need to be confirmed in a larger group of patients and controls. This confirmation (or validation) is the focus of this project. In the future, our test can be used to detect lung mesothelioma at an early stage. Unfortunately, this form of cancer is currently often detected late, partly due to the non-specific and late-occurring complaints experienced by patients. This limits treatment options and contributes to the very low survival rate. A diagnostic test that can detect the disease at an early stage will therefore have a positive effect on the survival rate of patients with lung mesothelioma in the long term.