Given that both ALS patients (Mitsumoto et al., 1998) and mutant SOD1 rodents (Lladó et al., 2006) succumb to disease due in part to diaphragmatic respiratory compromise, we next sought to focally reduce ephrinB2 expression in astrocytes in the region of the spinal cord containing respiratory PhMNs. Here, EFNB2 is linked to amyotrophic lateral sclerosis.