Fig. 2. IS promotes phosphatidylserine (PS) exposure in a time-dose response. RBC obtained from healthy subjects (n=10) were treated with different concentrations of IS (0.01, 0.09, 0.17mM) for 24h at 37^oC in an incubator with controlled oxygen in under normoxic (21% O₂) (white bars) or hypoxic (5% O₂) (black bars) conditions. Control RBC (CON-RBC) were incubated with TRIS-Glc-BSA in normoxia and hypoxia. RBC were analyzed by flow cytometry, and the results were expressed as Mean Fluorescence Intensity (MFI). **p<0.01; ***p<0.001 between normoxia versus hypoxia in the same group. ##p<0.01; ###p<0.001 between CON-RBC versus IS concentration in the same group (normoxia vs normoxia; hypoxia vs hypoxia).