<qa>  What is the name of the protein that is HER2 on the cell surface?The purpose of this study is to find out what effects, good andor bad, BIBW 2992 Afatinib has on patients and their advanced prostate cancer which does not respond to hormone or chemotherapy any more. Only patients with tumors which have an increased amounts of a protein called HER2 on their cell surface will be included. 