CD4 and rheumatoid arthritis: Most notably, overexpression of UBASH3A in CD4+ T cells of the control (Fig. 5A, B) and RA patients (Fig. 5C and D) suppressed the treatment-augmented cytokine production but not TNF-α protein in CD4+ T cells of the control, confirming the suppressive function of UBASH3A on activated TCR signaling in CD4+ T cells.