This notion is underscored by pre-clinical data suggesting that neutrophils are essential mediators of both pro- and anti-tumor inflammatory pathways (reviewed in Shaul and Fridlender18), including the potential of neutrophils to limit lymphocyte trafficking into malignant tumors, thereby limiting efficacy of programmed cell death 1 (PD-1) inhibition.19 The gene discussed is PDCD1; the disease is cancer.