(2R)-1,1-difluoro-2-palmitoyloxy-3-phosphopropane (XY-4) is an analog of 2-palmitoyl lysophosphatidic acid (LPA) in which the sn-1 hydroxyl has been replaced by two fluorines. It acts as a selective agonist of peroxisome proliferator-activated receptor γ (PPARγ) but does not stimulate LPA1, LPA2, or LPA3 receptors. PPARγ is a transcription factor of the nuclear receptor superfamily and has been implicated in atherogenesis.