STAT3 and myeloid sarcoma: To this aim, we decided to better characterize a circRNA deriving from STAT3 (Signal Transducer and Activator of Transcription 3), a gene necessary for pro-inflammatory cytokines signaling (Adamson et al., 2009) and that it is required for differentiation and expansion of Th17 cells, key players of MS disease activity (Brucklacher-Waldert et al., 2009).