Low KLK3 level observed in men with SHV [55, 57] and abnormal liquefaction [58]. Reduced sperm motility observed in men with low seminal KLK3 levels [59]. SNPs (rs266881, rs174776, rs1810020, rs266875, rs35192866) associated with male infertility [60]. This evidence concerns the gene KLK3 and male infertility.