For example, in 2018, a CancerSEEK multi-marker approach was designed based on the cirDNA mutation search and the analysis of proteomic biomarkers (CA-125, CA19-9, CEA, HGF, MPO, OPN, PRL, TIMP-1), which makes it possible to identify eight types of cancer (ovarian, liver, stomach, pancreatic, esophageal, colorectal, lung and breast cancer) with a sensitivity of 55% and a specificity of 99% [114]. Here, MPO is linked to cancer.