Studies of colitis-associated tumorigenesis and pancreatic ductal adenocarcinoma show a clear role for CXCR2 in tumor growth associated with attenuated MDSC recruitment in Cxcr2–/– mice (Ijichi et al., 2011; Katoh et al., 2013). Here, CXCR2 is linked to pancreatic ductal adenocarcinoma.