It can be caused by exposure to chemicals, drugs, radiation, infection, immune disease, and heredity; in about half the cases, the cause is unknown.
However in about half the cases, the cause is unknown. It can be caused by exposure to chemicals, drugs, radiation, infection, immune disease, and heredity.
It can be caused by exposure to chemicals, drugs, radiation, infection, immune disease, and heredity. However in about half the cases, the cause is unknown.
It can be caused by exposure to chemicals, drugs, radiation, infection, immune disease, and heredity. However in about half the cases, the cause is unknown.