CXCL8 and breast cancer: IL-8 signaling can activate and regulate PI3K (in neutrophils) [106], PKB/Akt [106], MAPK (cell proliferation in neutrophils [103,104], endothelial [305], and in some breast cancer cell lines) and the Raf-1/MAP/ERK1 cascade, p38 MAPK signaling cascade [107] and phospholipase C [306,307].