A major challenge in developing liver cancer drugs is that preclinical testing occurs in tumor models that do not accurately reflect human tumor features, causing drug candidates to later fail in clinical testing. Now, Singaporean researchers have grown organoids from liver tumors on specially engineered 3-D scaffolds. These organoids replicate important features of the original tumor, including genetic changes and intra-tumor heterogeneity, and could serve as tumor avatars for high-throughput drug screening.