CASP3 and malaria: To further investigate this, three distinct measures of apoptosis (YoPro, Annexin V and activated Caspase 3) were measured on Tregs both ex vivo and following stimulation with camptothecin (an activator of apoptosis) or PfSE in 28-month infants with low or high prior malaria incidence (PROMOTE no-chemoprevention control arm).