The Her2/Neu (c-erbB-2) proto-oncogene is a transmembrane receptor tyrosine kinase that is clinically indicated in a number of carcinomas. Overexpression of the c-erbB-2 protein has been associated with ductal breast cancer, as well as pulmonary and gastric adenocarcinomas. A correlation between Her2 and p53 has also been documented, as overexpression of both proteins has been associated with early invasion and metastasis in bladder cancer.