ABL1 and amyotrophic lateral sclerosis: In ALS spinal cord, motor neurons were strongly positive for active c-Abl at pre-attritional (Fig. 3e) and attritional (Fig. 3g) stages of degeneration as defined before [40] and were numerous (Fig. 3h), while spinal motor neurons in age-matched controls were scarcely positive for c-Abl (Fig. 3f, h).