PPARG and breast neoplasm: Specifically, activated PPARγ decreases the expression of C-X-C chemokine receptor type 4 (CXCR4) in CAFs, which represent the principal source of stromal cell-derived factor 1 alpha (SDF-1α) production, inhibiting their migratory capabilities and interfering with the autocrine and paracrine signaling loop acting to sustain breast tumor progression [20].