For many reasons, the zebrafish model is a powerful tool for studying various aspects of vertebrate diseases and normal developmental processes. They have a short generation time, are small, and are highly manipulatable for functional studies. Additionally, zebrafish are transparent as embryos. For these reasons as well as others, zebrafish have become a prevailing model for studying cell state transitions during vertebrate differentiation and in carcinogenesis. More recently, zebrafish have emerged as incredibly valuable when combined with genomics and biochemical studies. This is largely because zebrafish fertilization and early organismal development occur ex utero, and a single breeding pair can produce over 200 offspring per mating. Therefore, many thousands of cells can be harvested for complex studies that would otherwise require dissection and/or be very expensive if other vertebrate model systems were used.