CRLF2 is a receptor for thymic stromal lymphopoietin (TSLP). Together with the interleukin 7 receptor (IL7R), the protein and TSLP activate STAT3, STAT5, and JAK2 pathways, which control processes such as cell proliferation and development of the hematopoietic system. Two transcript variants encoding different isoforms have been found for this gene. Recombinant human CRLF2 protein, fused to His-tag at N-terminus, was expressed in E.coli.