Although little is known concerning the association of Ang-1 and Ang-4 in lung disease, the vast majority of research studies have focused on the association of Ang-2 with NSCLC, since elevated levels of the respective angiopoietin are detected in NSCLC cases, either in the serum or tissue of the examined patients [23,24,25,51,52,53,54]. This evidence concerns the gene ANGPT2 and lung disorder.