1. What blood test can be given to determine whether an MECFS patient has the proliferative B cells in their bloodstream, that rituximab and other drugs would eliminate from the bloodstream? 2. Would it be helpful at all after receiving this kind of treatment to also have one or two sessions of dialysis, to clear out the detritus from the bloodstream that is left behind after the rituximab treatment? 3. Is one of the reasons that this is possibly going to be helpful that clearing these proliferative b-cells would allow more space in the bloodstream for more red blood cells to be circulating, thus providing more oxygen to cells?