PCR clonality analysis. Shown are representative products produced by amplifying paraffin-extracted DNAs from three cases with the consensus FW3 and JH1 primers after electrophoresis and ethidium bromide staining. Single clonal bands are seen in all of these specimens except in the second biopsy from patient BA, which shows multiple clonal bands. Molecular weight markers are shown in the left most lane. Each lower rung of the polyclonal background ladders represents 3 nucleotides or one amino acid.