CHEK2 and neoplasm: <b>Methods:</b> A total of 1412 formalin-fixed paraffin-embedded (FFPE) tumor samples from mCRPC patients from 89 Spanish institutions within a centralized multicenter molecular testing program were analyzed using a standardized 38-gene-based next-generation sequencing (NGS) assay in a central laboratory (HRR OncoKit, Health in Code, Valencia, Spain), which included five clinically relevant HRR genes: <i>BRCA1</i>, <i>BRCA2</i>, <i>CHEK2</i>, <i>ATM</i>, and <i>CDK12</i>.