No significant correlations were found between the expression of CD20, FcγRIIb or their relative expression (ratio of MFI of CD20/FcγRIIb) to the CTI of rituximab or obinutuzumab in patients with SLE with r2, Spearman’s correlation coefficient, values of –0.31 (P = 0.19) and 0.25 (P = 0.29), respectively (Fig.  4A–C). Here, FCGR2B is linked to systemic lupus erythematosus.