KLK4 and neoplasm: As expected, among the overexpressed genes in tumor samples we found several genes previously identified as upregulated in this pathology, including several members of the matrix metalloproteinase family (MMP1, MMP3, MMP7, MMP10, MMP11), members of the kallikrein family of serine-peptidases (KLK6, KLK8, KLK10), as well as DPEP1 or PRSS22 among others [31-34].