TNFRSF21 and amyotrophic lateral sclerosis: Others have reported that astrocytes from SOD1G93A mice or sporadic human ALS patients regulate motor neuron cell death.31, 32, 37, 38 Here we demonstrate that blocking DR6 by 5D10 promotes motor neuron survival in motor neuron/astrocyte co-cultures containing astrocytes isolated from SOD1G93A mice, providing evidence that DR6 contributes to this neurotoxicity.