Figure 4From: Differential baseline and response profile to IFN-γ gene transduction of IL-6/IL-6 receptor-α secretion discriminate primary tumors versus bone marrow metastases of nasopharyngeal carcinomas in culture Statistical analysis of the relationship between IL-6 and IL-6Rα secreted spontaneously by NPC cell lines derived from primary and metastatic lesions. Regression curve constructed based on the relationship between IL-6 and IL-6Rα secreted at day 3 by all NPC cell lines tested including five P-NPCs (•) and three metastasis-derived NPC cell lines (■). The line was calculated by linear regression (r = 0.878; p < 0.01).Back to article page