Furthermore, methylation promoter areas in the cfDNA of pancreatic cancer patients have been found for the genes SPARC (secreted protein acidic and rich in cysteine), UCHL1 (ubiquitin carboxy terminal hydrolase L1), PENK (proenkephalin), and NPTX2 (neuronal pentraxin 2). This evidence concerns the gene PENK and familial pancreatic carcinoma.