TNFRSF11A and breast neoplasm: TNFRSF11A or RANK expression in breast tumours has been found predominately in those tumours with a high grade and proliferation index (Sigl et al. 2016); it has also received attention as a possible therapeutic agent (Sigl et al. 2016; Gonzalez-Suarez and Sanz-Moreno 2016; Jimi et al. 2013).