A Lund University-led ex vivo model suggests that precision-cut bladder tumor slices can preserve immune cells and remain functional for up to six days, enabling drug testing that reproduced nivolumab response patterns. The work supports a faster, tissue-preserving approach for preclinical immunotherapy screening. In parallel, a blood-based approach in Cancer Discovery reports that circulating tumor DNA plus immune profiling can identify neoantigens and reactive T cells from a simple blood draw. The study found broad overlap with biopsy-derived results and sometimes outperformed conventional sampling, pointing to a path for less invasive biomarker generation. Together, the studies shift attention toward immune-competent testing platforms—either tissue slices that retain microenvironmental context or liquid biopsy workflows that aim to capture tumor immunology at scale.