1.Introduction
ALL is a serious hematological system disease with highly aggressive characteristics(Terwilliger & Abdul-Hay, 2017). The lymphocytes proliferate and accumulate abnormally in the bone marrow, and transfer to other tissues and organs, causing systemic organs and tissue infiltrations and infections, seriously affecting normal hematopoietic function(Tan, Bertulfo & Sanda, 2017). ALL includes T-cell acute lymphoblastic leukemia (T-ALL) and B-cell acute lymphoblastic leukemia (B-ALL). Among them, T-ALL accounts for about 12% to 15% in pediatric ALL cases (You, Medeiros & Hsi, 2015). ALL is prone to occur in adolescents and children, and patients under 20 years old account for 60% of the total cases. The five-year event-free survival (EFS) of ALL is 60%-75%(den Hoed et al., 2015), significantly lower than other types of leukemia. With the development of new drugs and the application of new technologies, the survival rate of ALL patients has improved. In pediatric ALL, overall cure rates are approaching 90%,but in adult ALL, long-term survival rates are ~ 35 - 50%(Wei & Cleary, 2014), EFS and overall survival (OS) are still less than 70%, and the prognosis of relapsed and refractory ALL is poor(Sánchez-Martínez et al., 2019). Due to ethical reasons, clinically common refractory diseases are obviously impossible to replicate in human body to study the pathological and genetic mechanisms of disease occurrence(Adams et al., 1985). The remarkable functions of animal models are to: (1) simulate human genetic conditions and tumor growth microenvironment, (2) evaluate drug treatment effects, targets and ADR, (3) assess biomarkers related to tumor malignant transformation, (4) study the exogenous predisposing factors and pathogenesis of leukemia. At present, the animals commonly used to study ALL are mainly including mice, rats, zebrafish andDrosophila melanogaster (Milne, 2017). Among them, mice are very similar to humans in terms of genetics and hematopoietic system, and this unique advantage makes it important to establish mouse leukemia models to study the cellular molecular biology, biochemical and immunological characteristics, pathophysiological changes, pathogenesis, and drug treatment of human leukemia(Fortier & Graubert, 2010). Moreover, mice have the advantages of low price and good reproducibility, and the mouse xenotransplantation model and transgenic mouse model have been paid more and more attention and application. This article reviews the latest research progress of animal models of ALL.