A novel examination method for accurately evaluating the effectiveness of
treatment with an anticancer drug for the administration of the
anticancer drug targeting a tumor-associated factor receptor is provided.
In order to evaluate the effectiveness of trastuzumab (Herceptin.TM.) of
an anticancer drug, it was found to be meaningful to examine the
expression of MUC4, that is, a substance which interacts with
HER2/c-erbB-2 belonging to the epidermal growth factor receptor family on
the surface of and/or within the cell membrane. From this fact, in order
to treat various cancers with an anticancer drug targeting the
tumor-associated factor receptors, it was found to be meaningful to
detect previously the expression of intracellular ligands against the
receptors. The finding completes the present invention.