RRM2 and lung carcinoma: RRM2 is usually expressed at a high level in various cancers (e.g., colorectal, non‐small cell lung, breast, bladder, ovarian, pancreatic, head and neck, and lung carcinomas)17, 18, 19, 20 and is considered a prognostic marker for non‐small cell lung, cervical, and pancreatic cancers.21, 22