Several studies have shown the involvement of CD4+ helper T cells in tumor immunity and response to ICB (Zuazo et al, 2019; Kagamu et al, 2020; Li et al, 2020; Liu et al, 2020), which is distinct from their prominent role in inducing tumor-reactive cytotoxic T cells (Kreiter et al, 2015; Sahin et al, 2017; Borst et al, 2018; Zuazo et al, 2020). The gene discussed is CD4; the disease is neoplasm.