Briefly, it is well-established that cancer immunotherapeutics, like cytokines and oncolytic Ads, have been shown to elevate PD-1 expression in T cells or increase PD-1+ T cell population in the tumor tissues (Liu et al. 2024; 2020; Jiang et al. 2017; Cervera-Carrascon et al. 2020), and increased presence of Th1 cytokine IFN-γ led to PD-L1 upregulation by tumor cells (Tanoue et al. 2017; Boyerinas et al. 2015). The gene discussed is PDCD1; the disease is cancer.