Figure 4: ETS factors are important for normal development. Different classes of ETS transcription factors regulate different biological processes. The SPI class specifically regulates normal hematopoiesis, while other ETS proteins such as FLI1 are essential for vasculogenesis and angiogenesis. TEL2 might regulate both hematopoiesis and vasculogenesis. In this review we suggest that zebrafish are a powerful model system to study TEL2 function.