For example, KLK4 has a role in tooth development; KLK5, KLK7 and KLK14 are involved in skin desquamation; KLK6, KLK8 and KLK11 are involved in neural plasticity; KLK2 and KLK3 are involved in reproduction (liquefaction of semen); KLK1, KLK2, KLK4 and KLK6 are involved in ECM remodeling and tumor invasion [6], [18], [20]. This evidence concerns the gene KLK4 and neoplasm.