The downstream outputs of activated Rac signaling vary depending on the cell type or cancer context and include (1) cell cycle regulation; (2) signaling through JNK/SAPKs, p38-MAPKs, PAKs, the NF-kB pathway, WASP/WAVE complexes, and the BCL-2 family; (3) regulation of actin dynamics during leukocyte migration and phagocytosis; and (4) NADPH oxidase activation for reactive oxygen species (ROS) generation58,59. Here, MAPK8 is linked to cancer.