Ceramide-1-phosphate (C1P) is formed by the action of ceramide kinase (CK) enzymes on Cer.  C1P carry ionic charge at neutral pH and contain two hydrophobic chains making it relatively insoluble in aqueous environment.  Thus, C1P reside in the organelle where it was formed and is unlikely to spontaneously flip-flop across membrane bilayers.
C1P activate phospholipase A2 and is found, along with CK, to be a mediator of arachidonic acid released in cells in response to a protein called interleukin-1β (IL-1β) and a lipid-soluble molecule that transports calcium ions (Ca) across the bilayer, also known as calcium ionophore.  C1P was also previously reported to encourage cell division (mitogenic) in fibroblasts, block apoptosis by inhibiting acid SMase in white blood cells within tissues (macrophages) and increase intracellular free calcium concentrations in thyroid cells.  C1P also has known roles in vesicular trafficking, cell survival, phagocytosis ("cell eating") and macrophage degranulation.