CD1C and rheumatoid arthritis: Supporting this possibility, RNA-Seq and qPCR analyses confirmed that expression of IL-1β, IL-8, and MIP1α tended to be elevated in Mo and CD1c+ cDC but not CD141+ cells from SF samples of patients with RA compared with alternative synovial myeloid cells from individuals suffering CPPD crystal–associated arthropathy (Figure 4A and Supplemental Figure 6A).