This study examined the effects of low cytotoxic concentrations of multi-walled carbon nanotubes (MWCNTs) on the gene expression of thirteen selected cytokine genes in THP-1 macrophages. The production and applications of MWCNTs are augmenting, so their hazardous potential on human health must be well-characterized to develop effective therapeutics and appropriate safety protocols. This knowledge can be used to evaluate toxicity and eventually provide a foundation to manufacture engineered nanomaterials that could be safe and functional by design. This experiment revealed that MWCNTs, namely Cheaptubes, down-regulate the expression of key pro-inflammatory genes TNF (tumor necrosis factor) and IL1B (interleukin 1 beta), exhibiting an anti-inflammatory response at the transcriptomic level.