GJA1 and amyotrophic lateral sclerosis: In this context, it is worth noting that reactive astrocytes derived from a mouse model for the neurodegenerative disease Amyotrophic Lateral Sclerosis (ALS) express high levels of Cx43 that help sustain increased [Ca2+]i induced by mechanical stimulation or by ATP, effects that are inhibited by a Cx43-blocking peptide [14].