Research has been conducted on the genetic makeup of tumors, specifically focusing on tumor heterogeneity in various types of cancer, including cholangiocarcinoma, esophageal carcinoma, and lung cancer. The studies utilized multi-region sequencing to analyze the genomic landscape of tumors, revealing intratumoral heterogeneity and branched evolution. The findings suggest that multi-region sequencing can provide insights into the evolutionary trajectory of tumors and potentially identify novel targets for treatment.