Similarly, MTX-IR PsA patients showed comparable IHC scores for lining (1.92 ± 0.95) and sublining CD68+ cells (1.86 ± 0.96) than MTX-IR Abneg RA patients (2.00 ± 0.72 for lining CD68+ cells, p = 0.79; 1.46 ± 0.78 for sublining CD68+ cells, p = 0.25) (Fig. 1e–h). Here, CD68 is linked to rheumatoid arthritis.