Proto-oncogenes signal cells to grow and differentiate. However, they can become oncogenes due to mutations which result in the uncontrollable division of the cells, i.e. cancer. One way is a point mutation in a proto-oncogene. The consequence is changed protein product. Another way is gene amplification of DNA segment containing a proto-oncogene. As the result, the encoded protein is overexpressed. The third way is translocation. As the result of translocation, proto-oncogene can be controlled by the different promoter and expressed inappropriately.