LCN2 and lung cancer: The reasons to choose to these genes are: i) data from public domain ONCOMINE shows that Cp, LCN2 and Postn are upregulated in lung cancer verse normal lung tissues; ii) at least in some reports, these genes are upregulated in certain types of tumor samples; iii) the products of these genes can be detected in serum or liquid biopsy [10–12], which is applicable in early diagnosis.