The invention provides conjugates that consist of a drug moiety agent and a cell binding agent that target human fibroblast growth factor receptor 3 (FGFR3). These conjugates have therapeutic use as they are designed and tailored to target a specific cell population and deliver a powerful cytotoxin inside the cell. The conjugate of the present invention has significant advantages over other conjugates known in the art by providing a targeted tumor therapy as well as bystander activity to neighboring cells in an important oncology receptor that is only moderately expressed.
