PENK and colorectal carcinoma: In a recent study, we linked changes in methylation patterns of blood mononuclear cells with CRC-associated microbiota.56 We found that several gene promoters, including SFRP1, 2, and 3, PENK, NPY, ALX4, SEPT9, and WIF1, were hypermethylated in the CRC tumoral tissues and blood, compared to healthy donor tissues and blood.