CD8⁺Tregs have a proapoptotic phenotype. (A-B) Immunoblot analysis of pro- and antiapoptotic proteins derived from in vitro-generated alloantigen-induced CD4⁺ and CD8⁺ Tregs. Representative immunoblots are depicted in (A), and cumulative results of quantitative densitometry analysis from 4 to 9 replicates per blot are shown in (B). *P < .05; **P < .01; ***P < .001.