Additionally, proteomics studies involving the secretome derived from T-cells and B-cells demonstrated specific protein signatures in the exosomes of patients receiving PD-1 inhibitors before treatment and in tumor-associated B-cells, suggesting that these protein signatures can be used as promising predictive markers for PD-1 inhibitors regarding activation of PD-1+ T-cells treated with PD-1 inhibitors [115,116]. The gene discussed is PDCD1; the disease is neoplasm.