Schalper et al. investigated serum IL-8, a potent regulator of neutrophil chemotaxis, in patients receiving ICI and observed a positive correlation between circulating IL-8 and both peripheral neutrophil counts and tumor infiltrating neutrophilis as well as a negative association with response rates and survival outcomes (Schalper et al., 2020). The gene discussed is CXCL8; the disease is neoplasm.