IL7R and rheumatoid arthritis: As the molecular pathway of lTSLP signaling involves binding to its receptor complex TSLPR and the IL-7Rα, which activates the downstream signal transducer and activator of transcription 5 (STAT5) (14), we thus investigated the STAT5 event in lTSLP-treated PBMCs of HC and RA patients in the presence or absence of LPS stimulation.