Growth factor receptor-bound protein 7, also known as GRB7, is a protein that in humans is encoded by the GRB7 gene. The product of this gene belongs to a small family of adaptor proteins that are known to interact with a number of receptor tyrosine kinases and signaling molecules. This gene encodes a growth factor receptor-binding protein that interacts with epidermal growth factor receptor (EGFR) and ephrin receptors. The protein plays a role in the integrin signaling pathway and cell migration by binding with focal adhesion kinase (FAK). Alternative splicing results in multiple transcript variants encoding different isoforms, although the full-length natures of only two of the variants have been determined to date. GRB7 is an SH2-domain adaptor protein that binds to receptor tyrosine kinases and provides the intra-cellular direct link to the Ras proto-oncogene. Human GRB7 is located on the long arm of chromosome 17, next to the ERBB2 (alias HER2/neu) proto-oncogene. These two genes are commonly co-amplified (present in excess copies) in breast cancers. GRB7, thought to be involved in migration[citation needed], is well known to be over-expressed in testicular germ cell tumors, esophageal cancers, and gastric cancers.