Inferred from mouse: The receptor for Thymic stromal lymphopoietin (TSLP) consists of Cytokine receptor-like factor 2 (CRLF2, TSLPR) and Interleukin-7 receptor subunit alpha (IL7R). Ba/F3cells expressing human IL7R or human TSLPR, or both stimulated with TSLP induce phosphorylation of Signal transducer and activator of transcription 3 (STAT3) and Signal transducer and activator of transcription 5A or B (STAT5A, STAT5B or STAT5), only in cells expressing both receptors (Reche et al.2001). This is a black box event since there is no experimental details confirming binding of STAT3 and STAT5 to the receptor complex.