CXCR4 and lymph node disorder: For example, in patient 15 with PD after chemotherapy, despite a nearly 50% reduction of TLUCXCR4 and MTV CXCR4 from baseline, there were new emerging lymph node diseases detected by both 18F-FDG and 68Ga-pentixafor PET/CT at follow-up, consistent with the clinical response classification of PD.