**6.1. Oncology diseases-specific biomarkers-**

Haab etal. defined a panel of five serum proteins significantly expressed in serum between prostate cancer patients (33) and 20 controls [18]. In addition, this team has also identified 84 proteins with differentially relative abundance between diagnosed lung cancer patients and healthy controls [19].

In a similar approach, Wittekind and colleagues reported a set of proteins as biomarker candidates associated with hepatocellular carcinoma [20]. Nowadays, several studies have been performed and focused on biomarker identification in several oncological pathologies; for example: In ovarian cancer, 11 proteins have been identified by Amonkar etal. [21]; Sreekumar etal. identified a panel of proteins as biomarker candidates in colon carcinoma cells [22]; Díez etal. has identified differentially expressed proteins in B-cell chronic lymphocytic leukemia which are related with target therapeutics [23]. Previously, Below and coworkers have developed an antibody microarray to immunophenotype 1100 leukemia and lymphomas according to the abundance of a panel of 82 antigens or cluster of differentiation (CD) characterized at the surfaces of lymphocytes [24].
