The mitogen-activated protein kinase (MAPK) signaling pathway is activated by a number of extra and intracellular stimuli including cytokines, growth factors, and hormones as well as stressors such as oxidative and ER stress. This pathways plays a key role in the regulation of many cellular processes including proliferation, differentiation, the stress response, motility, growth, differentiation, survival, and death. Abnormal MAPK signaling may contribute to increased or uncontrolled cell proliferation and/or resistance to apoptosis. To study this complex pathway, several tools are available, from the pathway specific arrays for an initial screen, to phospho-specific ELISA tests for individual target validation. This post aims at helping you to easily identify tools to explore this pathway in your samples (from arrays to phospho-ELISAs). However, I could not start without showing you once more one of these eye-catching illustrations of cell signalling pathways. I’ll let you explore it to dig out the MAPK protein cascade among all of them (a kind of Where’s Wally for the researcher !).