CellCept, manufactured and distributed by Roche Laboratories, is an immunosuppressant drug administered to patients who have recently undergone an organ transplant. Nearly 25,000 people are given CellCept each year to help prevent the recipient's body from rejecting the transplanted organ. CellCept has been linked to a variety of severe, sometimes fatal, side effects, including cancer of the lymphatic system, miscarriages and birth defects in pregnant patients, and PML, which is a debilitating neurological disease. These side effects were not included in the warnings on the original packaging for CellCept.