A human monoclonal antibody against the pro-inflammatory mediator interleukin-8 (IL-8; CXCL8), with potential antineoplastic activities. Upon administration, HuMax-IL8 directly binds to IL-8, thereby inhibiting the binding of IL-8 to its receptors CXCR1 and CXCR2. This inhibits activation of IL-8-mediated signaling transduction pathways, which decreases proliferation of susceptible tumor cells. Also, HuMax-IL8 effectively blocks binding of IL-8 to neutrophils and inhibits neutrophil activation and recruitment towards sites of inflammation, which reduces inflammation. IL-8, a member of the CXC chemokine family, is upregulated in a variety of cancer cell types and inflammatory diseases; it plays a key role in tumor cell proliferation, endothelial cell proliferation, and cancer stem cell (CSC) renewal.