TNF and monocytic leukemia: Already available in vitro studies have indicated possible immunotoxicity of CuO NPs mediated by cytotoxicity towards immune cells (human blood lymphocytes) (16), RAW264.7 (murine macrophage cell line) (19), or potent induction of proinflammatory cytokine TNF-α in differentiated human THP-1 cells (human monocytic leukemia cell line) (17).