For example, whole genome and whole exome sequencing has identified point mutations in the gene encoding the protein TREM2 (triggering receptor expressed on myeloid cells 2) that correlate with a significantly increased risk of developing Alzheimer’s disease (AD) (Guerreiro et al., 2013b; Jonsson et al., 2013). Here, TREM2 is linked to early-onset autosomal dominant Alzheimer disease.