LTF and breast cancer: Studies specifically designed to determine BC constituents [32,33,34] have shown that BC contains several bioactive components, including various growth factors, immunoglobulins, leukocytes, antimicrobial elements and lactoferrin (LF) [32,35], which induce positive effects on bone metabolism [36,37,38,39,40], both in vivo and in vitro [41,42].