Decision Letter: Intercellular Propagation of Extracellular Signal-Regulated Kinase Activation Revealed by In Vivo Imaging of Mouse Skin

The study investigated the propagation of extracellular signal-regulated kinase (ERK) activation in mouse skin, revealing two types of propagation: SPREAD, a sporadic burst of ERK activation, and a more sustained wave-like response to wounding. The research demonstrated that both types of ERK activity depend on metalloprotease activity and MEK activation. The wound-response waves were particularly significant due to their potential physiological importance. The study faced challenges in correlating SPREAD frequency with factors like age or sex and in establishing a clear relationship between SPREADs and cell cycle progression. The authors acknowledged limitations in their data and suggested that further research could clarify these mechanisms.