CTSB and nasopharyngeal carcinoma: AGR2, CTSB, and CTSD were significantly upregulated in LMNPC compared to NNET (P<0.01), and AGR2 and CTSD were also upregulated in LMNPC when compared to primary NPC (P<0.05), whereas no change of CTSB between LMNPC and primary NPC (P>0.05) was observed.