By harnessing the host s innate and/or adaptative immune systems,cancer immunotherapy is a promissing approach to treat cancer.However,recent data from clinical trials in which immunotherapeutics have been implemented indicate that we would benefit from a better knowledge on the mecanisms underlying these novel approaches.While preclinical models have been extensively used to obtain proof of concept and to better understand the mode of action of some of these products,they often remain conundrums and poor predictors of the outcome in clinical trials.One way by which we can increase our insight in the immunological processes required for succesfull immunotherapeutic treatments is by immunomonitoring patients receiving such therapeutics.The use of transcriptomics,proteomics and state of the art immunomonitoring methods are crucial in identifying prognostic biomarkers and/or signatures of responses.We have used these methods to follow patients enrolled in a phase Ⅱb clinical trial which combined a MUC1-expressing MVA vector with the standard treatment of Non Small Cell Lung Carcinoma.Predictive biomarkers have been identified.This data set is essential in the design of future clinical trials.Refuelling this information in novel preclinical models will allow us to gain insight in the mode of action of our product and render it more efficient.