TSLPR (thymic stromal lymphopoietin receptor) also known as CRLF2 (cytokine receptor-like factor 2) is a member of type I cytokine receptor. It binds its ligand TSLP (thymic stromal lymphopoietin) as a heterodimer with IL7R. TSLP ligand is produced by epithelial cells in order to activate dendritic cells, and is involved in inflammation, allergic responses as well as B-cell precursor proliferation and survival. The interaction between TSLP and its heterodimeric receptor activate STAT3, STAT5, and JAK2 pathways, which control processes such as cell proliferation and development of the hematopoietic system. High expression of CRLF2 is associated with a poor prognosis in adult and high-risk pediatric cases of B-ALL (B-cell acute lymphoblastic leukemias).