Methods, network control nodes, network nodes and user equipments for assisting the updating of neighbor cell information when a new cell is introduced, or added, to an already existing radio access network are described in this disclosure. According to an example embodiment a signal is transmitted, from a first network control node 10 associated with RAN1 to a second network control node 20 associated with RAN2. This signal comprises a cell identity CI1, e.g. a Local Cell Identity LCI1, of the newly introduced cell C109, which is added to RAN1. Next, the second network control node 20 of RAN2 receives the signal comprising the cell identity CI1 of this newly introduced cell C109. In response, the second network control node 20 transmits, to at least one user equipment 30e associated with the RAN2, a signal comprising the received cell identity CI1 of the newly introduced cell C109 as well as a request to the at least one UE 30e associated with RAN2 to search for the newly introduced cell C109 of RAN1, which is controlled by network node 40.