Apoptosis was measured as previously described (19 (link)) using the annexin V-fluorescein isothiocyanate (annexin V-FITC) Apoptosis Detection Kit (BD Biosciences, San Diego, CA) according to the manufacturer’s instructions. Following treatment, annexin positive cells were quantitated by FACS analysis (Becton Dickinson, Ranklin Lakes, NJ) using FlowJo Software (Tree Star, Inc, Ashland, OR) and FCS Express 7 Software (De Novo Software Inc.). The percentage of annexin positive was calculated and the delta between treated and untreated control was determined.