For example a search for “breast cancer” could return discussions of ovarian cancer or colon cancer due to the association of these diseases in the BRCA1 and 2 syndromes, or the use of trastuzumab (Herceptin, Roche/Genentech) for a variety of conditions, due to the primary indication of trastuzumab in the use of breast cancer over-expressing hER2. Here, ERBB2 is linked to ovarian cancer.