The accepted pathway of MAPK activation is through a three kinase phosphorelay arrangement. However, as [Johnson][1] explains in his Perspective, new work has established an alternative way for a MAPK called p38a to be activated ([ Ge et al .][2]). Apparently, a scaffolding protein called TAB1 that is devoid of any known catalytic activity is able to interact with p38a, inducing its autophosphorylation and consequent activation. [1]: http://www.sciencemag.org/cgi/content/full/295/5558/1249 [2]: http://www.sciencemag.org/cgi/content/short/295/5558/1291