RAD21 and lung cancer: This section discusses the roles of 16 biomarker genes - BUB3, CCNB1, CCNB2, CDC20, CDCA8, CDK1, CENPF, CENPI, KIF18A, KNTC1, MAD2L1, NDC80, NUP37, PCNA, RAD21, and ZWINT - related to lung cancer discovered from non-treatment studies.