MAPK8 and breast carcinoma: Consistent with JNK-driven expression of IL1A/B in cancer cells, treatment with CM from MKK7-JNK-expressing MDA breast cancer cells increased the production of CXCL10 in fibroblasts compared with CM from MDA-control cells, and this increase was blunted when fibroblasts were treated with CM from MKK7-JNK(mut)-expressing cells (Fig. 7g).