In order to respond to various external or internal environmental stimuli,organisms develop complex cell signaling pathways consisting of receptors,kinase cascades,and other regulatory proteins.Recently,JMCB has published a number of research articles uncovering new members (Perez et al.,2012;RayegoMateos et al.,2013) or regulating mechanisms (Suoet al.,2012;Won et al.,2012;Zhang et al.,2013) of various cell signaling pathways.In this issue,more research works provide new information for understanding the molecular mechanisms and functions of TGF-β signaling as well as other cell signaling pathways for pathological responses.