The slow development of dendritic spines observed with apoE4 may also be important in the poor recovery from damage by other insults, such as traumatic brain injury (Teasdale et al., 1997; Chiang et al., 2003; Zhou et al., 2008) or HIV-dementia (Burt et al., 2008; Chang et al., 2011). The gene discussed is APOE; the disease is dementia.