PDCD1 and non-small cell lung carcinoma: By applying MALDI- MSI method to pretreatment biopsies of advanced NSCLC patients responding and nonresponding to PD-1 immunotherapy, they found that an increased level of neutrophil defensin 1, 2 and 3 expression is related to a positive immunotherapy response, suggesting that neutrophil defensins could serve a biomarker to predict the response to immunotherapy [161].