CDK9 and mature T-cell and NK-cell non-Hodgkin lymphoma: We summarize recent advances in the treatment of R/R PTCL from the 2023 ASH Annual Meeting, highlighting novel agents targeting EZH1/2, JAK1, PI3K, KIR3DL2, CD38/CD3xCD28, or CDK9, as well as therapeutic regimens in combination with stem cell transplantation, immunomodulators, epigenetic modifying agents, or CD30/CD16A bispecific antibodies.