The Grb7 family is a rapidly emerging group of Src homology (SH)2 domain-containing signalling proteins that currently contains three members, Grb7, 10 and 14. These proteins possess a conserved multidomain structure, including a central region exhibiting significant homology to the Caenorhabditis elegans protein Mig10. Differences in tissue expression and SH2 binding selectivity suggest that these adaptor proteins function in a tissue-specific manner to link specific receptor tyrosine kinases (RTKs) and other tyrosine phosphorylated proteins to as yet uncharacterised downstream effectors. Interestingly, Grb7 proteins exhibit differential expression amongst a variety of human cancers and cancer cell lines. Consequently, these proteins not only are likely to perform a fundamental signalling role, but may also modulate RTK signalling in cancer cells.