In terms of the variety of extracellular nucleotide-degrading enzymes and purinergic receptors, which assemble as homo- or heterocomplexes and vary in composition in different CNS cell types, more intense research has to be performed to clarify short- and long-term implications of purinergic signaling in ALS. This evidence concerns the gene P2RX4 and amyotrophic lateral sclerosis.