The role of IL-8 in cancer development and its impact on immunotherapy resistance

Tumors are structures of high complexity. Plurality of their structural and functional components - heterogeneity, diversity, directionality, interdependence and integration of signaling pathways - seem to follow isolated local rules, whereby a superordinate structure remains largely unknown. Understanding the complexity of cancer is the mainstay in finding determinants and developing effective therapies. Interleukin 8 (IL-8) is a potent pro-inflammatory chemokine that is significantly elevated in many different tumor entities. In contrast to its initially postulated anti-tumor properties, an increasing number of studies have been published in recent years linking this chemokine with tumor-promoting features and poor prognosis. This review summarizes the current state and diversity of the role of IL-8 in the development of cancer.