ALK and cancer: For example, tyrosine kinase inhibitor crizotinib was originally designed to inhibit c-MET involved in tumor proliferation and metastasis but is also used as an anti-cancer medication for the treatment of non-small cell lung carcinoma (NSCLC) by targeting echinoderm microtubule-associated protein-like 4 (EML4) fused anaplastic lymphoma kinase (ALK) [31,32].