Precision medicine. This post continues the discussion on how we can make sense of clinical data in the absence of outcomes in the context of precision medicine – a concept that drives much of what we do on a research basis. The fundamental idea is that clinical care in pediatric epilepsies can be personalized and tailored to underlying etiologies. With continual progress in gene curation and variant interpretation alongside clinical knowledge, we typically expect that treatment suggestions are immediately implemented after the discovery of the causative genetic etiology. For example, a child with early onset epileptic encephalopathy is found to have a gain-of-function variant in SCN8A and is almost immediately started on a sodium channel blocker such as Trileptal. However, to what extent is this the case? In the context of precision medicine, how precise are we exactly?