HLA-DRA and leukemia: Although upregulation of the total MHC II was evident in lysates from caspase-2 RNAi-silenced human leukemia cell lines, and B-cells isolated from gene-targeted mice (HLA-DRα and I-Eα, respectively), no variation of MHC II was evident in FACS analysis of APCs isolated from caspase-2−/− mice when compared to cells from control littermates.