Among them, the CD34+ cluster (F2) is associated with differentiation and progenitor-like status, the inflammatory CD74hi HLAhi cluster (F-5) and a CXCL12+ SFRP1+ cluster (F-6) highly express IL16, which has been a known RA druggable target. The gene discussed is CXCL12; the disease is rheumatoid arthritis.