Atg2A (TG2 autophagy related 2 homolog A) is a 1,938 amino acid protein that belongs to the ATG2 family and may play a role in vesicle assembly. Encoded by a gene that maps to human chromosome 11q13.1, Atg2A is conserved in chimpanzee, dog, cow, mouse and rat, and exists as four alternatively spliced isoforms. Undetected in adult tissues, including heart, brain, placenta, lung, liver and skeletal muscle, Atg2A regulation may act as a distinct indicator of autophagic programmed cell death. Atg2A is upregulated in both etoposide- and doxorubicin-induced apoptosis of HeLa cells, suggesting that Atg2A functions as a novel biomarker of topoisomerase II inhibitor-mediated apoptosis. Atg2A associates with Atg2B, indicating that these two related proteins also functionally interact. Atg2A frameshift mutations are linked to gastric and colorectal carcinomas with high microsatellite instability and may contribute to cancer development by deregulating the autophagy process.