OSBP and viral infectious disease: The concept of membrane contact sites (MCSs) in virus infection was established by the discovery of oxysterol-binding protein (OSBP) as the target of minor enviroxime-like compounds (Arita et al., 2013), and as the effector of PI4KB (Arita, 2014) or of PI4KA (Wang et al., 2014) in virus replication.