?The Gas2 protein is thought to play a role in apoptosis by acting as a cell death substrate for caspases. Gas2, a component of the microfilament system, is cleaved by a caspase (caspase-3 or caspase-7) at Asparagine 278 during apoptosis. The cleaved form of Gas2 dramatically induces the re-arrangement of the Actin cytoskeleton and causes potent changes in the shape of the affected cells. Gas2 is a cytoskeleton and peripheral membrane protein that co-localizes with Actin fibers at the cell border and along the stress fibers in growth-arrested fibroblasts. Gas2 is mainly membrane-associated, but when hyperphosphorylated it will accumulate at membrane ruffles, indicating Gas2 involvement in that process. Gar22 (Gas2-related protein on chromosome 22), also designated growth arrest-specific protein 2-like 1 (Gas2-like1), belongs to the Gas2 family and contains one CH (calponinhomo-logy) domain. It is thought to be involved in the cross-linking of microtubules and microfilaments.