This proto-oncogene causes cancers (carcinomas and sarcomas) and is found in the avian myelocytomatosis virus. It has been identified in several avian tumours, and encodes a nuclear protein with a leucine zipper motif.
If translocated, it can cause Burkitt's lymphoma, if amplified, it can cause lung, breast, and cervical carcinomas. It is found in both chickens and has an analogue in humans which is located on the long arm of chromosome 8.