01698nas a2200289   4500000000100000000000100001008004100002260001500043653003000058653001900088653002500107653001700132653001100149653002300160653001400183653001400197653002300211653001500234653002700249100001800276700001700294245005200311300001200363490000800375520101100383022001401394       2019                            d  c2019-06-0710aBiological Specimen Banks10aCarcinogenesis10aCoculture Techniques10aGene Editing10aHumans10aModels, Biological10aNeoplasms10aorganoids10aPrecision Medicine10aStem cells10aTumor Microenvironment1 aDavid Tuveson1 aHans Clevers00aCancer modeling meets human organoid technology  a952-9550 v3643 aOrganoids are microscopic self-organizing, three-dimensional structures that are grown from stem cells in vitro. They recapitulate many structural and functional aspects of their in vivo counterpart organs. This versatile technology has led to the development of many novel human cancer models. It is now possible to create indefinitely expanding organoids starting from tumor tissue of individuals suffering from a range of carcinomas. Alternatively, CRISPR-based gene modification allows the engineering of organoid models of cancer through the introduction of any combination of cancer gene alterations to normal organoids. When combined with immune cells and fibroblasts, tumor organoids become models for the cancer microenvironment enabling immune-oncology applications. Emerging evidence indicates that organoids can be used to accurately predict drug responses in a personalized treatment setting. Here, we review the current state and future prospects of the rapidly evolving tumor organoid field.  a1095-9203