PLAT and multiple sclerosis: In a multiple sclerosis (MS) model of experimental allergic encephalomyelitis (EAE) [157], the inhibition of microglial activation through tPA knockout (tissue plasminogen activator, an essential element for microglia activation) leads to a delayed onset of the disease but increased severity and delayed recovery from the neurological dysfunction, which suggests that microglial activation is harmful during the onset of the disease but beneficial in the recovery phase [157].