Consistent with our data showing lowered PD-1 expression of CD4+ and CD8+ tumor-infiltrating T cells upon rMVA-CD40L treatment, Ngiow et al.47 recently reported that agonistic CD40 antibody-induced IL12 was responsible for PD-1 downregulation on CD4+ and CD8+ T cells infiltrating murine mammary and renal carcinomas. Here, CD4 is linked to neoplasm.