The phase diagram of strong interaction has been a subject of intense theoretical and experimental research. One of the big questions in this regard is whether a critical endpoint is associated with the phase transition of strongly interacting matter. There have been rapid theoretical developments to answer this question. On the experimental side, a tremendous effort is put forward to hunt for the critical point in collisions of atomic nuclei. This article gives an experimental overview of some of the key results for critical point searches, mainly focusing on net-proton number fluctuations in nuclear collisions.