P2RX7 and amyotrophic lateral sclerosis: The studies about the involvement of purinergic signaling in neurodegenerative and neuroinflammatory conditions are certainly convincing (Volonté et al., 2003; Franke and Illes, 2006; Burnstock, 2008; Khakh and North, 2012; Sperlágh and Illes, 2014; Tewari and Seth, 2015; Burnstock, 2016; Burnstock, 2017a; Burnstock, 2017b) and now flourishing also on ALS and P2X7, in particular (Volonté et al., 2011; Volonté et al., 2012; Volonté et al., 2016; Sebastião et al., 2018; Cieślak et al., 2019; Ruiz-Ruiz et al., 2020).