Janus kinase 3 mutation expression and function in microsatellite stable colorectal cancer

This preprint presents a literature-based Letter to the Editor on the interpretation of Janus kinase 3 (JAK3) alterations in microsatellite-stable colorectal cancer. It distinguishes genetic variants, gene expression, and functional evidence, and discusses the limitations of extrapolating findings across tumor types and experimental models. It emphasizes cellular context, molecular characterization, and clinical validation when assessing potential associations with immune checkpoint inhibitor response. No new datasets were generated or analyzed. This manuscript has been submitted to the Brazilian Journal of Oncology. This preprint version has not been peer reviewed.