Our laboratory is analyzing changes in the immune microenvironment in early-phase versus advanced-phase treatment using an anti-programmed cell death-1 (PD-1) antibody, which is an immune checkpoint inhibitor. Although immune checkpoint inhibitors have advantages over other cancer therapies because they are effective even for advanced cancer, administration of these drugs during earlier phases of disease is associated with greater efficacy. However, the mechanism responsible for this greater efficacy remains unknown. Therefore, I have been studying how changes in the cancer immune microenvironment vary by the timing of immunotherapy initiation using mouse models. I have found that changes in the cytokine environment in regional nodes likely play an important role in this mechanism. In future studies, I will conduct an exhaustive analysis of the cancer microenvironment using mass cytometry and single cell analysis with the goal of elucidating the mechanisms behind antitumor immune responses at the molecular level using big data. I want to work as a researcher for a pharmaceutical company after graduation. I hope I can directly contribute to creating effective treatments for patients.