This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Crizotinib is used in the treatment of : 
Select and explain. 
A. FLT-3 +ve Non small cell carcinoma of lung, B. ALK +ve Non small cell carcinoma of lung, C. FLT-3 +ve  Acute myeloid leukemia, D. BRCA-2 +ve metastatic breast carcinoma
B: ALK +ve Non small cell carcinoma of lung
Answer: B: ALK +ve Non small cell carcinoma of lung 
Explanation: Crizotinib inhibits anaplastic lymphoma kinase (ALK), hence used in ALK mutation positive non small cell carcinoma of lungs.