DLK1 and early-onset autosomal dominant Alzheimer disease: Elevated DLK signaling has been associated with traumatic injury and implicated in Alzheimer’s disease and other neurodegenerative conditions (Asghari Adib et al., 2018; Huang et al., 2017; Jin and Zheng, 2019; Le Pichon et al., 2017; Tedeschi and Bradke, 2013).