To determine the signal intensities of the tau-specific bands in Western blots in distinguishing probable CJD and non-CJD, the relative gray values of Band-B and -C in every blot of each CSF sample were counted after equilibrated with the gray value of the recombinant protein tau441 that was recognizable by all used tau antibodies. The gene discussed is MAPT; the disease is Creutzfeldt Jacob disease.