ERBB2 and breast cancer: Unlike other tyrosine kinase receptors, like her2/neu for example, gene amplification and/or mutations in the IGF-1R gene are distinctly uncommon, occurring in less than ten percent of breast cancers [21] and rarely in pediatric wild-type gastrointestinal stromal tumors [22], pancreatic adenocarcinomas [23], and Wilms' tumors [24].