This is even more since AML arises in the BM where (i) various cells abundantly express RANKL (e.g., [12,14,16]) and since (ii) the tightly controlled microenvironment plays an important role in transformation and development of malignant hematopoietic disease as well as chemotherapy resistance [52,53]. The gene discussed is TNFSF11; the disease is acute myeloid leukemia.