Human cancer cells acquire somatic mutations in the NCL genes which may confer a growth advantage (CLN1/PPT1, CLN2/TPP1, CLN3, CLN4/DNAJC5, CLN5, CLN6, CLN7/MFSD8, CLN8, CLN10/CTSD, CLN11/GRN, CLN12/ATP13A2, CLN13/CTSF, CLN14/KCTD7, as well as SGSH, and CLCN6) (www.sanger.ac.uk/genetics/CGP/cosmic/) (66). The gene discussed is PPT1; the disease is cancer.