Growth factorA growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Usually it is a secreted protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes. Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells. They often promote cell differentiation and maturation, which varies between growth factors.
Ankylosing spondylitisAnkylosing spondylitis (AS) is a type of arthritis characterized by long-term inflammation of the joints of the spine typically where the spine joins the pelvis. Occasionally areas affected may include other joints such as the shoulders or hips. Eye and bowel problems may occur as well as back pain. Joint mobility in the affected areas generally worsens over time. Although the cause of ankylosing spondylitis is unknown, it is believed to involve a combination of genetic and environmental factors.
