RRM2 and non-small cell lung carcinoma: Recent studies have confirmed that the expression of regulating ribonucleotide reductase subunit M2 (RRM2), a small subunit of the ribonucleotide reductase complex, promotes the progression of various cancers, including NSCLC, ovarian cancer, and bladder cancer, by inducing the accumulation of deoxyribonucleoside triphosphates to support rapid cell division [17,18,19,20,21].