Apoptosis is regulated by death domain (DD) and/or caspase recruitment domain (CARD)bcontaining molecules and a caspase family of proteases. CARD containing cell death regulators include RAIDD, RICK, BCL10, Apaf 1, caspase 9 and caspase 2. Apoptosis repressor with CARD is a CARD domain containing protein that interacts with caspase 2 and 8 to inhibit enzymatic activity of caspase 8. Apoptosis repressor with CARD suppresses apoptosis induced by cell death adapters FADD and TRADD and by cell death receptors Fas, TNFR 1, and DR3. The mRNA of Apoptosis repressor with CARD is primarily expressed in skeletal muscle and cardiac tissue. The nuclear isoform (1/Nop30) may be involved in RNA splicing and the cytoplasmic isoform (2/Myp) may inhibit apoptosis.