Crizotinib, an anaplastic lymphoma kinase (ALK)/ROS1/c‐MET inhibitor, improves outcomes in ALK‐positive non‐small cell lung cancer (NSCLC) but can cause crizotinib‐associated renal cysts (CARCs), a rare yet clinically relevant adverse effect. The gene discussed is ALK; the disease is non-small cell lung carcinoma.