MAPK3 and neoplasm: The observations in this study made using diverse systems in vitro cells embedded in 3D collagen I gels, KRS−/+ heterozygous mice, and clinical tumor tissues, support the notion that KRS functions together with p67LR/integrin α6β1 receptors to mediate cell dissemination from (tumor) cell masses via the laminin adhesion-dependent regulation of ERK1/2 and paxillin expression and activity.