KLK6 has been involved in the regulation of myelin sheath volume (Blaber et al., 2002) and degradation of a β-amyloid peptide, a function associated to different neurodegenerative diseases such as Alzheimer’s disease, in which it has been proposed as a biomarker (Diamandis et al., 2000). Here, KLK6 is linked to early-onset autosomal dominant Alzheimer disease.