P2RX7 and Parkinson disease: In contrast to these transcriptomic data, numerous experimental studies have shown that microglial P2X7 protein levels are elevated in human AD brains, in multiple rodent amyloidosis models (93–98), in the PD rat model 6-OHDA as well as in the spinal cord of ALS patients and SOD1 mutant mice that serve as ALS animal models (99–101).