To determine if IL-25 is expressed at the metastatic site, metastatic lung sections from tumor-bearing MMTV-PyMT mice were stained with IL-25 by IHC, but there was no IL-25 expression in both tumor and paratumor area (Fig. 1B), suggesting that IL-25 is mainly derived from the primary tumor sites. The gene discussed is IL25; the disease is neoplasm.