Recent studies suggest that patients with mesothelioma undergoing immunotherapy (e.g., T cell therapies) or chemotherapy (e.g., gemcitabine) showed enhanced tumor immune cell infiltration (e.g., CD4 + T helper cells and CD8 + T cells) and prolonged survival (de Gooijer et al., 2020; Gray and Mutti, 2020). The gene discussed is CD4; the disease is mesothelioma.