CXCL8 and cancer: The reviewed data will show how erlotinib-provoked IL-8 elevation has three negative effects on treatment efforts: (1) decreasing quality of life by generation of the neutrophilic erlotinib rash, (2) IL-8 mediated enhanced migration or invasion of cancer cells in a similar manner as has been shown for neutrophils’ chemotaxis along an IL-8 gradient, and (3) enhanced neutrophil migration to and into tumors with ensuing growth contribution by factors brought to tumors by these neutrophils.