Restoration of ERK2 phosphorylation by DiC10 in PMN treated with sphingosine. PMN (2 × 10⁶/mL) were pretreated for 30 minutes with 10 μmol/L sphingosine followed by incubation for 30 minutes with 200 μmol/L DiC10 (panel I) or treated with 10 μmol/L sphingosine alone (panel II) or 200 μmol/L DiC10 alone (panel III). The PMN were then primed with 10⁻⁷mol/L fMLP and then challenged with EIgG (column A), challenged with EIgG alone (column B), were not treated (column C), or were stimulated with 10⁻⁷ mol/L fMLP (column D). ERK2 phosphorylation was determined by Western blotting. See Fig 2B for an example of control values.