NR4A1 and neoplasm: In T cells, overexpression of NR4A1 in combination with activating protein-1 (AP-1) inhibits the expression of effector genes, such as Jund and Naf1, which reduces their secretion of interferon-gamma (IFN-γ) and Interleukin-2 (IL-2), leading to a significant decrease in the tumor-killing effect of T cells (67).