<s>[INST] <<SYS>> This is a medical question of type : information <</SYS>> What is (are) Lung Cancer ? [/INST] Lung cancer occurs when malignant tumors form in the tissue of the lung. The lungs are a pair of sponge-like organs. The right lung has three sections, called lobes, and is larger than the left lung, which has two lobes. </s>