 Next to surgical approaches in functional handicapped patients, a standard medical therapy is not available. Therefore, in most cases, a watch-and-wait strategy is followed. Taking into account the genetic background of segmental overgrowth patients, mTOR is a promising target for a possible medical treatment. For example, because the direct molecular consequence of PTEN loss-of-function is an aberrant activation of the mTOR pathway, targeting mTOR holds the promise of a causative treatment in PTEN-positive segmental overgrowth patients. 