It was examined that hypermethylation of KLK10 CpG island functions a crucially significant role in tumor-specific loss and downregulation of KLK10 mRNA and protein expressions in ALL, breast, and prostate cancers (Olkhov-Mitsel et al., 2012; Roman-Gomez et al., 2004; Sidiropoulos et al., 2005). This evidence concerns the gene KLK10 and prostate cancer.