P2RX7 and amyotrophic lateral sclerosis: In particular, in P2X7−/−/superoxide dismutase (SOD)1-G93A mice, the most studied ALS animal model [18], the clinical onset of ALS was anticipated, and the disease progression worsened, thus suggesting that the participation of P2X7 has some beneficial function, at least in the early phases of the disease [19].