Researchers led by Prof. HU Zheng from SIAT, uncovered a polyclonal origin of tumors, challenging the traditional clonal evolution theory. Using a DNA barcoding system in mouse models and genomic analysis of human colorectal samples, they demonstrated that colorectal precancers often arise from multiple distinct cellular lineages, which later transition to monoclonality as tumors progress. These findings, published in Nature, provide critical insights into the early evolution of colorectal cancer and offer new opportunities for preventing malignant transformation.