C57Bl/6 and OPN−/− mice were purchased from Jackson Laboratories. B6.SJL-PtrcAPep3B/BoyJ mice were bred in-house. CXCR4flox/flox mice were generated as described 23 (link) and were a kind gift from Y. Zou, Columbia University. EP1−/−, EP2−/−, EP3−/−, and EP4flox/flox mice were generated as described 24 (link)–26 (link). Conditional mice were bred to Ubc-Cre/ERT2 mice from Jackson. Female olive baboons, Papio anubis, were housed individually in conventional caging of the Biological Resources Laboratory, University of Illinois (UI) at Chicago. Primate research was approved by the UI Animal Care and Use Committee (IACUC). The IACUC of IUSM approved all protocols. The IRB of IUSM approved human subject research and informed consent was acquired from all volunteers.