Although the non-canonical pathway activator Wnt5a is an important regulator of lung development, and generally is an inhibitor of canonical Wnt signalling, elevated levels of Wnt5a in lung metastases of human sarcoma [84] has been reported and thus questions the role of non-canonical Wnt signalling as a general inhibitor of lung cancer. This evidence concerns the gene WNT5A and lung carcinoma.