More recently, a five-gene (budding uninhibited by benzimidazoles 1 homolog beta (BUB1B), centromere protein A (CENPA), never in mitosis gene a-related kinase 2 (NEK2), Rac GTPase-activating protein 1 (RACGAP1), ribonucleotide reductase M2 (RRM2)) tumor grade signature (MGI for molecular grade index) was developed to recapitulate tumor grade. The gene discussed is RRM2; the disease is neoplasm.