FDPS and breast neoplasm: It remains an open question whether the responders to bisphosphonates in the AZURE trial were positive for GGPS1 and/or FDPS—both of which have been implicated in oncogenesis [58,59,60], and thus, MAF-negative breast tumors might have responded well to bisphosphonate therapy due to the presence of its targets—a question for validation in a prospective clinical study.