“…the mechanisms leading to hypercalcemia associated with malignant tumors are divided into three categories: humoral hypercalcemia caused by secreted factors (such as PthrP, i.e., parathy-roid hormone-related protein, or inflammatory cytokines), local osteolysis due to tumor invasion or humoral factors (only in case of impaired kidney function) and absorptive hypercalcemia due to excess vitamin D produced by cancer cells [2,3].…”