The expressions of epithelial-mesenchymal transition (EMT) markers in NPC and their correlations with patient disease-free survivals. The hematoxylin and eosin (H&E) staining features of EC, MSEC, SC, and SCC subtypes (line 1, A1, B1, C1, and D1). Preserved E-cadherin expression in EC (A2), MSEC, (B2), and SCC (D2) in contrast with loss of expression in SC (C2) are shown in line 2. N-cadherin IHC staining with overexpression in SC (C3) and absent expression in EC (A3), MSEC (B3), and SCC (D3) are shown in line 3. CD44v6 IHC staining with a lack of expression in EC (A4) and expression in MSEC (B4), SC (C4), and SCC (D4) is shown in line 4. Twist IHC staining showing no expression in EC (A5) and MSEC (B5) and overexpression in SC (C5) and SCC (D5) (line 5). Snail IHC staining showing no expression in EC (A6) and MSEC (B6) and overexpression in SC (C6) and SCC (D6) (line 6). Cyclin D1 IHC staining with no expression in EC (A7) and MSEC (B7) and overexpression in SC (C7) and SCC (D7) (line 7). All histological images were taken using the same magnification shown in A1. Panel E1 shows the disease-free survival curve of all 1077 NPC patients. Panel E2-7 shows the survival curve of 1077 patients with IHC staining of EMT markers. The 5-year disease-free survival rates of NPC patients with low- vs. high-level expression. The indicated markers are: 60.8% vs. 69.4% for E-cadherin (E2), 71.9% vs. 58.3% for N-cadherin (E3), 75.1% vs. 62.7% for CD44v6 (E4), 73.5% vs. 47.1% for Twist (E5), 74.0% vs. 62.7% for Snail (E6), and 77.2% vs. 55.3% for cyclin D1 (E7). The P-values for all comparisons are less 0.01. The largest difference in 5-year disease-free survival was in the Twist expression comparison, with a difference of 26.5%.