GT-7 and GT-38 immunostain 3R and 4R containing tau inclusions in cognitively normal and PART cases. Fixed, paraffin-embedded tissue from AD, PART, and no cognitive impairment control entorhinal cortex were stained by IHC with PHF1, novel tau mAbs GT-7 or GT-38, 3R tau specific RD3, or 4R tau specific RD4.