PTH and neoplasm: We had found that a pharmacologic intervention to modulate the osteoblasts and osteoclasts using parathyroid hormone (PTH) and zoledronic acid (ZA), followed by intracardiac tumor injection on day 5, and subsequent quantification of tumor cell numbers 24 hours later on day 6 (as illustrated in Fig. 5a), resulted in a decrease in stromal cells in the bone marrow with a concurrent increase in tumor cell count (Fig. 5b-c) [13].