POLE and rectal cancer: A single-cell Seurat object was built with three distinct samples: normal tissue adjacent to rectum, rectal cancer complete response to immune-therapy (CR), MSI-high (Microsatellite Instability)/TIB-high (tumor indel burden), and sigmoid cancer, progression disease under immune therapy (PD), and POLE-mutant/TMB-UH (tumor mutation burden ultra-high > 100) (Figure 3A).