Updated publication reference for PubMed record(s): 29186685. C-C chemokine ligand 2 (CCL2) plays pivotal roles in tumor formation, progression, and metastasis. Although CCL2 expression has been found to be dependent on the nuclear factor (NF)–κB signaling pathway, the regulation of CCL2 production in tumor cells has remained unclear. Mammalian target of rapamycin complex 1 (mTORC1) is a protein kinase that is activated in various tumor cell types. We have now identified a noncanonical pathway for regulation of CCL2 production that is mediated by mTORC1 but independent of NF-κB. Multiple phosphoproteomics approaches identified the transcription factor forkhead box K1 (FOXK1) as a downstream target of mTORC1, with dephosphorylation of FOXK1 in response to mTORC1 activation resulting in transactivation of the CCL2 gene. Inhibition of the mTORC1-FOXK1 axis attenuated insulin-induced CCL2 production as well as the accumulation of tumor-associated monocytes-macrophages and tumor progression in mice. Our results suggest that FOXK1 directly links mTORC1 signaling and CCL2 expression in a manner independent of NF-κB, and that CCL2 produced by this pathway contributes to tumor progression. Specific inhibition of FOXK1 may thus be a potential therapeutic strategy for cancer.