CHEK1 and mature T-cell and NK-cell non-Hodgkin lymphoma: To better characterize the molecular heterogeneity and physiopathology of nodal PTCLs, and to provide more rationality in its treatment, we evaluated the prognostic impact of cyclin A2 (CCNA2), DNA topoisomerase Iiα(TOP2A), checkpoint kinase 1 (CHEK1), factor nuclear kappa B (NF-kB1), inhibitor of nuclear factor kappa B kinase subunit β (IKBkB), and vascular endothelial growth factor 1 (VEGF1)gene expression and CCNA2, TOP2A, CHEK1 and NF-kB1 proteins in nodal PTCL at a single cancer treatment center in Brazil.