At the molecular level, impaired tumor growth in the three PDXs treated with p38 MAPK inhibitor correlates with downregulation of the chemokines CXCL-1 and CXCL-2 and the cytokine IL-6, which are all known to play key roles in colon tumorigenesis [29, 33, 40]. Here, CXCL1 is linked to neoplasm.