The fact that we observed RANK-L expression in benign epithelium adjacent to OGC-IC NST significantly more often than in the control cases (73% vs. 11%, Fisher’s test: p = 0.009), could further support the hypothesis that OGC-IC NST occur in a specific hormonal setting, which affects not only tumor cells, but a whole “field” of mammary tissue or the entire mammary gland, and promotes RANK-L expression. The gene discussed is TNFSF11; the disease is neoplasm.