Cancer genomics data for circulating cell-free DNA

We searched the NCBI BioProject database and downloaded 1,012 experiments with original sequences from 14 projects, involving 7 major types of head and neck cancer, lung cancer, breast cancer, prostate cancer, gastric cancer, colon cancer, and liver cancer. For sequence reading, we performed preprocessing steps and variant calling, followed by a series of filtering steps to remove non-functional variants and minimize false positives, which gave us a refined list of 6981 variants.