CXCR2 and neoplasm: As already mentioned, the binding of IL-8 to CXCR2 in non-muscle cells is known to activate STAT and ERK signaling [65,66], but also to activate NF-κB [71] and p38 MAPK signaling [65], and each of these signaling pathways is implicated in tumor-induced skeletal muscle atrophy [7,31,32,39].