Her work on controlling elements and gene regulation was difficult and was not immediately understood or accepted by her contemporaries; she described the reception of her research as "puzzlement, even hostility". Nevertheless, McClintock continued to develop her ideas on controlling elements. She published a paper in 1953 where she presented all her statistical data, and undertook lecture tours to universities throughout the 1950s to speak about her work. She continued to investigate the problem and identified a new element that she called "Suppressor-mutator" ("Spm"), which, although similar to "Ac/Ds", displays more complex behavior. 