In CIS, a negative correlation was found between CXCR4 and CD74 levels on B cells (r = –0.44, P = 0.01; Fig. 2D), and CXCR4/CD74 expression ratios positively associated with fatigue (r = 0.53, P = 0.003; Fig. 2E), an independent predictor of rapid CIS to CDMS transition 15. Here, CD74 is linked to in situ carcinoma.