Sam Kleeman, MD PhD

Thrilled to announce I have matched into the Internal Medicine-Research Track Program at @WeillCornell! #Match2026 @TheNRMP 🎉

Immune surveillance can be a double-edged sword. ⚔️ In @Nature, Endeavor Awardee @JanowitzTobias shows that the same B cell response targeting NMDAR-expressing breast cancer tumors can mature into antibodies that trigger autoimmune disease. #Sec9" target="_blank" rel="nofollow noopener">nature.com/articles/s4158…

Delighted to share that my PhD research studying the connection between anti-cancer immunity and autoimmunity, supervised by @JanowitzTobias and @Lab_FURUKAWA @CSHL has been published in @Nature today.

Pleased to share our new collaborative work on the link between anti-cancer immunity and anti-NMDAR encephalitis. Clinical sample, mouse model, BCR seq, cryo-EM, electrophysiology, behavior, etc. @JanowitzTobias @KleemanSam and more. nature.com/articles/s4158…

We are pleased to share our paper connecting anti-cancer immunity to autoimmune mediated neuropsychiatric disease. @KleemanSam @Lab_FURUKAWA @miriamferrer95 @jpreall @Mayo_AING @CSHL @NorthwellHealth @TBBCF @SimonsFdn @TheMarkFdn @NIH @BarbMarte nature.com/articles/s4158…

Early-career researchers thrive at CSHL! From the Janowitz lab, Sam Kleeman (@KleemanSam) has been selected for the 2026 Emerging-Generation Award, and Alice Wang has received a Predoctoral Fellowship award. Read more here! cshl.edu/janowitz-lab-m…

Spatial transcriptomics is powerful—but fragile. Our new @NatureGenet paper shows that cell-segmentation errors are widespread and can obscure much of what we think we’re learning. nature.com/articles/s4158…

Honored to receive a 2026 Emerging-Generation (E-Gen) Award from @the_asci! I am incredibly grateful to my mentors Tobias Janowitz (@JanowitzTobias) and Hiro Furukawa (@Lab_FURUKAWA) for their support throughout my PhD @CSHL @CSHLsbs.

Our new paper in @TheLancetPsych NMDAR-antibody is very different from most forms of psychosis. - Rapid Onset - Complex, Polysymptomatic features - Often starts with mood - Dynamic over a short timescale - plus some more specific characteristics url-shortener.me/2XKW

Where do cancers start? In the liver, not all cells are the same. The liver is divided into 3 “zones,” and each specializes in different metabolic tasks. We show in @Science that where a mutation occurs in a liver lobule can determine a cell’s fate. science.org/doi/10.1126/sc… (1/9)

Proud to share @niseto’s (new PI @TheCrick) paper: As a postdoc (@CSHL/@HopkinsMedicine), he found #NETs in necrotic tumors—I shrugged. But he looked closer: NETs block tumor vessel perfusion, causing necrosis, hypoxia, EMT & #Metastasis. nature.com/articles/s4158… @JHU_BDP @Nature

@CKBrierley @NatureGenet @ArbachHratch Congratulations!!!!

🚨🚨Paper out! 🚨🚨 Delighted to share our work, now published in @NatureGenet 🧬! shorturl.at/94s5S We identified a targetable, chromothripsis-associated genetic event in blast phase (BP) MPN, a particularly poor prognostic subtype of acute leukaemia. 1/n 🧵👇

This is a really important paper - immunogenic tumour associated antigens seem to be more associated with aberrantly expressed extragenic RNA than the classical mutations nature.com/articles/s4301…

"Why do I no longer enjoy my favorite food and activities?" - an important question from our patients with cancer and cachexia! Cancer is a disease of the whole body, including the brain. @KepecsLab @Pignatelli_Lab @miriamferrer95 @CancerGrand @CSHL science.org/doi/10.1126/sc…

V pleased to share our paper on the immune landscape of CSF in MS and other conditions cell.com/cell-reports-m… now out in @CellRepMed Fun and stimulating collaboration with co-first author @ChristieGasperi and senior authors Maria Ban, Steve Sawcer and Bernhard Hemmer

A commonly inherited genetic variant of human PCSK9 drives breast cancer metastasis and associates with reduced patient survival. @CellCellPress PCSK9 drives pro-metastatic genes by repressing LRP1. Anti-PCSK9 antibody has breast CA metastasis suppressive effects 🙏@RockefellerUniv @NCIsysbio @NCI @Lunduniversity Hess Family. sciencedirect.com/science/articl……tweetorial by amazing @wenbin_mei x.com/wenbin_mei/sta…

Thrilled to share our paper now out @Nature delineating #plasticity during #CRC #metastasis, a fantastic collaboration led by @andrewrmoorman @elliebenitez11, and @f_cambuli from the @KarunaGaneshLab and @dana_per lab! nature.com/articles/s4158… rdcu.be/dYAVK. A 🧵

nature.com/articles/s4159… We are excited to share our latest research on the structural and functional mechanisms underlying anti-NMDAR encephalitis. Our study reveals that three antibodies, isolated from different patients, bind to distinct regions of the NMDARs 1/n)

Very happy to share our study published @JCO_ASCO ! ascopubs.org/doi/full/10.12… ➡️Patients with mUC with NECTIN4 amplifications (occurring in app. 25%) show remarkable responses to single-agent EV, with a 96% objective response rate compared to 32% in non-amplified cases. NECTIN4 amplification predicts long-term survival benefits! ➡️Our data highlights the correlation between NECTIN4 targetability and EV response, which is consistent with findings obtained for other ADCs, such as the Her-2-targeting ADC trastuzumab-deruxtecan (T-DXd) ➡️Interestingly, NECTIN4 amplification occurs frequently across solid tumors (common also in TNBC & NSCLC!) ➡️NECTIN4 amplification has potential as a tumor-agnostic biomarker for NECTIN4-targeting therapies (like Her2-targeting T-DXd within DESTINY-PanTumor02 Phase II) ➡️ Conclusion: ADC response is dependent on target gene expression! We need better biomarker stratification for future trials in mUC, especially as the number of available ADCs increases (also Trop2, Her2..) ➡️Outlook: Validation of this biomarker for EV/P! Thanks to our great collaborators: @Markuseckstein3 @HolzelMichael @ViktorGruenwald @JoshMeeks @KuppeChristoph @IEO_HolzelLab @UniklinikBonn @UniBonn and to the support from @dfg_public (UroAgeCare!) & @EKFStiftung @BMBF_Bund Happy to discuss the data with the GU community! @ASCO @JCOPO_ASCO @OncoAlert @urotoday @PTarantinoMD @Uroweb @drenriquegrande @PGrivasMDPhD @amerseburger @DrYukselUrun @tompowles1 @Uromigos @OncoBellmunt @montypal @DrChoueiri @neerajaiims @shilpaonc @VPrasadMDMPH @sonpavde @DrRosenbergMSK @Dr_Aggen @jonchou05 @koshkin85