TP53 and amyotrophic lateral sclerosis: PPP1R13B encodes an apoptosis-stimulating protein that is able to interact with p53, regulating neuronal differentiation and specifically enhancing p53-induced apoptosis that was identified as an apoptotic mode of motor neuron cell death in the spinal cord of ALS patients (Table 2, Fig. 4, and Supplementary Table 1) [153–155].