To determine the cellular processes affected by JNK signaling in breast cancer cells, global gene expression changes induced by these loss‐ and gain‐of‐function approaches were analyzed in parallel to identify genes that were most sensitive to modulation of JNK activity (Fig 2A) and by gene ontology (GO) using Database for Annotation, Visualization and Integrated Discovery (DAVID). This evidence concerns the gene MAPK8 and breast cancer.