The relative cobblestone area–forming cell activity of cells that undergo transwell migration in response to lysophospholipids. Transwell assays were performed with Lin^– Sca⁺ Kit⁺ cells and the agonists shown for 6 hours. Cells that migrated into the bottom wells were then assessed in CAFC (5-week) assays. The results are shown as the relative number of CAFCs compared with the starting population (ie, cells straight after flow-cytometric enrichment). Freshly enriched cells had a CAFC frequency of 1 in 514 for 10⁵ cells. Results are the mean ± SEM of 3 experiments.