Illustration showing monoclonal antibodies (light blue/orange) being used to treat bone tissue (turquoise) affected by osteoporosis. Osteoporosis causes bones to become weak and brittle. Bone tissue is constantly being broken down and replaced. Osteoporosis occurs when the creation of new bone doesnt keep up with the loss of old bone. Women after menopause are more susceptible to this condition, which is attributed to a decline in ovarian hormone production. Monoclonal antibodies (mAbs) are proteins secreted by a cloned line of cells which have been engineered to respond to a particular target, in this case the cells that break down bone.