Rea, AnnaSantana-Hernández, SaraVillanueva, JavierSanvicente-García, MartaCabo, Mariona, 1991-Suárez Olmos, JesúsQuimis, FabricioQin, MengjuanLlorens, EduardBlasco-Benito, SandraAlari-Pahissa, ElisendaCelià-Terrassa, ToniMontagut Viladot, ClaraAlbanell Mestres, JoanGüell Cargol, Marc, 1982-López-Botet, M. (Miguel)Muntasell i Castellví, Aura, 1972-2025-05-082025-05-082025Rea A, Santana-Hernández S, Villanueva J, Sanvicente-García M, Cabo M, Suarez-Olmos J, et al. Enhancing human NK cell antitumor function by knocking out SMAD4 to counteract TGFβ and activin A suppression. Nat Immunol. 2025 Apr;26(4):582-94. DOI: 10.1038/s41590-025-02103-z1529-2908http://hdl.handle.net/10230/70330Transforming growth factor beta (TGFβ) and activin A suppress natural killer (NK) cell function and proliferation, limiting the efficacy of adoptive NK cell therapies. Inspired by the partial resistance to TGFβ of NK cells with SMAD4 haploinsufficiency, we used CRISPR-Cas9 for knockout of SMAD4 in human NK cells. Here we show that SMAD4KO NK cells were resistant to TGFβ and activin A inhibition, retaining their cytotoxicity, cytokine secretion and interleukin-2/interleukin-15-driven proliferation. They showed enhanced tumor penetration and tumor growth control, both as monotherapy and in combination with tumor-targeted therapeutic antibodies. Notably, SMAD4KO NK cells outperformed control NK cells treated with a TGFβ inhibitor, underscoring the benefit of maintaining SMAD4-independent TGFβ signaling. SMAD4KO conferred TGFβ resistance across diverse NK cell platforms, including CD19-CAR NK cells, stem cell-derived NK cells and ADAPT-NK cells. These findings position SMAD4 knockout as a versatile and compelling strategy to enhance NK cell antitumor activity, providing a new avenue for improving NK cell-based cancer immunotherapies.application/pdfeng© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/s41590-025-02103-zCancer immunotherapyImmunotherapyinfo:eu-repo/semantics/openAccess