CPN2 and neoplasm: In order to further screen and find the downstream target of CPN2 in the pathogenesis of LUAD, we used the protein interaction bioinformatics software and TCGA database analysis to find that the expression of COL1A2, COL1A1, and COL3A1, in the key target of the Akt pathway, was significantly positively correlated with the expression of CPN2. As recently reported, these genes belonged to the fibrillar collagen family members and showed a significant effect in tumor development from multiple aspects (36–38).