In this report, we describe a signaling pathway from PERK through C/EBPδ in cancer cells, which contributes to expression and secretion of CXCL8/IL-8 and CCL20 (Fig. 8), two chemokines that have well-documented tumor promoting effects through direct action on cancer cells as well as various immune cells [40, 48]. The gene discussed is CCL20; the disease is cancer.