In melanocytes, PMEL undergoes a series of proteolytic processing steps, including the cleavage by BACE2 (β-secretase 2) that releases an amyloidogenic Mα fragment into the endosomal lumen (containing N-terminal region (NTR), PKD (polycystic kidney disease domain) and RPT domains), which is further cleaved to produce a fibril-forming CAF (core amyloid fragment) and a fibril-associated RPT fragment (Watt et al., 2009; Leonhardt et al., 2011; Rochin et al., 2013; Bissig et al., 2016; Hee et al., 2017). This evidence concerns the gene BACE2 and polycystic kidney disease.