The FGFR-encoding gene was studied extensively with regard to its expression,hyperamplification, mutation, translocation, or such in various cancer cells.As a result, novelfusion polypeptides in which the FGFR3 polypeptide is fused with a differentpolypeptide wereidentified and isolated from several types of bladder cancer-derived cells andlung cancer cells.The use of a fusion polypeptide of the present invention as a biomarker inFGFR inhibitor-basedcancer therapy enables one to avoid side effects in cancer therapy and controlthe therapeuticcondition to produce the best therapeutic effect, thereby enablingindividualized medicine.
