If you develop symptoms of GvHD after the T-cell infusion, you must return to the clinic within 72 hours. Most cases of GVHD occur within 60 days of the T-cell infusion. If you have GvHD, you will receive AP1903 by vein and possibly steroids by mouth or by vein. If your doctor thinks it is needed, you may receive one more dose of AP1903 by vein 24-72 hours after the first dose.